Yes, there's no way that two same wallets (Mycelium) with the same seed, will generate two different wallets unless the other has a passphrase.
As you can see, when you restored the seed to your current installation, it keeps on generating the same wallet as the Android Myceium.

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By the way, since you can see the transactions.
Search the output of transaction #4 and check it it's now spent. If it is, it's most likely that your previous deleted IOS Mycelium was a fake.
If not spent, it may be the correct app and you still have a chance if you can guess your passphrase or found the correct seed phrase.

To check if it's spent:

• First, change the blockexplorer option in the settings, among the choices, blockchain.info(com) is the one with easy indicator if the output was spent.
  (that's in "Menu/...->Settings->Block explorers->Bitcoin->blockchain.info")
• Go to 'Transactions' tab, tap transaction #4 (should have red amount for 'send-out txns', the amount should be the "missing funds")
  It will be highlighted, then click "Show Details" above.
• Click on the "Hash" and you will be redirected to blockchain.com through your default browser.
• In that page, look for the outputs ("to" or the green arrow pointing right);
  spent outputs have a "red globe" icon next to it instead of a "green globe" (unspent). the change should be green since it's still in your wallet.

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Last note: It's not recommended to write the BIP39 passphrase on the same paper as the seed phrase, or it will defeat its purpose.

So it's the other way around in comparison to your previous reply, hmm...
But it still subjected to the fact that you've sent the funds to your IPhone Mycelium that 'you think' has the same seed as your Andoid Mycelium.
And the final balance "0.000X BTC" that you're seeing is the change of that #4 transaction.
The rest of the balance is in that deleted wallet, it's basically same thing.

If HCP's suggestion to create the second HD account didn't work,
you'll have to search for another seed phrase backup or keep on restoring it with your commonly used passphrase.

He had posted that in his "information update" in Post number 11.
What I get is: From android to Iphone (almost all funds), then Iphone to Kraken (just a portion, left a change with large funds).

It's indeed advanceable to copy paste addresses, then double-check.

However, the statement about "most mistake by newbies" leading to loss of funds due to typo error as the isn't correct.
Because there's a "checksum" in addresses whether it's P2PKH, P2SH or Bech32, so if at least one character is typed incorrectly, the user wont be able to click 'send' at all
unless the wallet is poorly designed or the person is just extremely unlucky that he typo~ed a valid address.
BTW, Bech32 can only be either all upper-case or all lower-case characters, not mixed.

I've setup a watchtower following the tutorial using localhost and it worked even without 'SSL Certificate' (only for localhost I believe),
I've used these options:

Which is saved in the config file as:

Run electrum as daemon.

Lastly, in the client, "Tools->Preferences->'Lightning' tab->Use a remote watchtower" enable it but leave it blank.

it's on testnet BTW:

It's not updating real-time at my end, I have to close the 'local watchtower window' and open it again to update the list.
And newly opened channels wont show up unless Electrum client restarts, done 1 lightning transaction or it's just me.

It also falls to scenario 1 or 2 in the list in my previous reply of "possible scenarios".

See, if your IOS and Android Myceliums are different wallets (due to IOS having a passphrase or just a different seed entirely) and you've sent the balance from Android to IOS.
The change "0.000X BTC" that you're seeing is the change of that "from Android to IOS transaction", thus balance of the Android Mycelium.
The change of "from deleted IOS wallet to Kraken" transaction should be in that deleted wallet, not in the Android Mycelium.

And since the original deleted IOS Mycelium seems to be a different wallet (I mean not a copy of your Android Mycelium),
when you restored using the seed of  "Android Mycelium", the restored wallet to IOS Mycelium only has the "0.000X BTC" balance which is the change of the "from Android to IOS transaction".

With all the statements, it seems like you've added a passphrase that made the deleted IOS Mycelium a totally different wallet; if not, it has a different seed to begin with.
Specially the very first paragraph in the OP:

That's a weird feature then. Yes, maybe left it as it is because there was no efficient way to validate the transaction.
There's now testmempoolaccept RPC which they can utilize to fix that, but not all servers use Bitcoin Core or supported Bitcoin Core versions.

Good thing they moved to psbt.

Since the transaction has a signature,
I assume that it was signed with one prvKey before the raw transaction (HEX) is imported to Electrum.

Now the issue: Electrum has a bug where you can immediately broadcast an imported RAW transaction (except PSBT) whether it's signed correctly or not.
If the transaction is in HEX, "broadcast" button will be available even if a transaction is unsigned/partially signed.
But since it's invalid, the server where you're connected to wont relay it.

With that, it should be signed once more by one of the other two cosigners.

Actually, use that as your first option, next is the seed phrase.
Because the contacts, address & history labels, invoices and wallet-specific settings aren't backed-up by the seed.

Then copy it to "wallets" folder inside the default (non-portable) data directory: electrum.readthedocs.io - where-is-the-electrum-datadir-located

BTW, portable's data directory is in "electrum_data" folder where the executable (electrum-portable.exe) is located, in case you want to copy the config file and others.

It's stated in the OP that the android phone is his wife's.

A little TL;DR of the whole thread: He said that he restored the same seed to his Iphone and His wife's Android;
but only the Android showed the correct balance so he sent the bitcoins to his IPhone.
Deleted the Mycelium app in IPhone after a transaction.
Then the issue occurs.

AFAIK, Mycelium uses the same 'change address format' as the output's format, like if you're sending to a SegWit address, Mycelium will use SegWit change address.
(but that info won't help with the recovery of your funds, only to identify which output is the change).

Anyways, there shouldn't be any issue with the funds being sent to your change address, it's also recoverable from the seed phrase (or with passphrase).

But like I've mentioned:
"Seed Phrase A" will still recover the same set of (receiving) addresses and change addresses from 'Mycelium A'.
If you've restored "Seed Phrase 'A' with a Passphrase", it will recover an entirely different set of addresses and change addresses.
So, if you have set a passphrase in the deleted IOS mycelium, all you have to do is to restore the same seed but with the correct passphrase.
Wrong Passphrase will work but will create a new-different wallet.

No problem.
If you have no further concerns, feel free to lock the thread using the "lock topic" button at the lower-left side of the page.
You can always unlock it using the same button.

Do not do that while using a watch-only wallet, because the entire balance of the address derived from the swept private key will be sent to that wallet.
In your case, use the import option in the new wallet creation window.

That only happens when there's at least one wrong character in the private key.
It has a checksum so that if you've typed it wrong, the inputted private key will be invalid. With that, look for possible typos.
By the way, it's case-sensitive.

But based from the blurred image in the appstore and ETF's post, it looks like it's longer than a "WIF PrvKey" which is what Electrum supports.
Maybe it's in a different format? Can you tell the first character and total number of characters? (please do not share the actual prvKey to anyone)
And also, the lock icon beside it seems important; Is it displayed as locked/unlocked in your app?

Not at all, your wallet is just a collection of private keys to move your coins which are stored in the blockchain.
With a passphrase (actually "BIP39 passphrase"), it will just generate a wallet with entirely different set of private keys, the balance of the wallet without a passphrase/different passphrase wont be affected.

If you want to restore the wallet with "0.000X BTC" balance, you can just restore the seed without the passphrase.

Assuming that the device where it's restored is secured, there wouldn't be any major circumstances on trying to restore it with a passphrase.

Developers do not usually do that, most of the time, there's always cross-platform compatibility.
I'm also pretty sure Mycelium haven't changed derivation path in the earlier versions.

These are the possible scenarios that could have happened based from your statements.
(Refer to the OP for the quoted parts):

• Since IOS Mycelium didn't have any balance in "Status at this point", the IOS Mycelium could have been a different wallet entirely.
  So after sending the bitcoins from your Android to the zero-balance-Mycelium in "Action taken", all that's left to the Android Mycelium is the change which is the "0.000X BTC".
  When you restored the seed from Android to the IOS in "Actions taken later", It displayed the same balance as the android which is the change of that transaction.
  
  
• This is a variation of the first scenario but recoverable: You could've added a "Passphrase" to the seed when restoring it to the IOS app.
  If this is the case, try to restore the seed again but now, check "I have a passphrase" and after typing the seed, you'll have to type exactly the same passphrase that you've used before.
  This is because adding a passphrase to the seed phrase will generate a different set of keys so it will create an entirely different wallet.
  
  
• Are you 100% sure that it's the same seed even with the passphrase or it doesn't have a passphrase? Yes?
  If your previous balance isn't too high, you might have used most of it as "transaction fee" for the transaction in "Action taken".
  That transaction did nothing but to send it to the same wallet. Because sending bitcoins between wallets with the same seed is pointless since it's basically a 'send-to-the-same-wallet' transaction.
  
  
• Or it's actually displaying the correct balance and "0.000X BTC" was just previously displayed as "0.X mBTC".
  In that case, it's just the Cryptocurrenct denomination, my example above have the same value.
  
  

The default paths for different systems are written in that link.
For Windows10, it should be in in "C:\Users\"Your_Username"\AppData\Roaming\Bitcoin"
The shortcut: Use 'Search' or 'Run' (WinKey+R), type %appdata%, then go to bitcoin folder.

Then create the config file if you haven't created one yet.
The easiest way is to: right click on an empty space inside the data directory while nothing is highlighted, select "New->Text Document".
Rename "New Text Document.txt" into "bitcoin.conf" (including the extension from ".txt" into ".conf").
If the extension is hidden, you can display it using the file explorer menu above "View" and check "File name extensions".

Then open bitcoin.conf using your txt editor and type datadir=E:\Bitcoin on the first line, save it.
(replace "E:\Bitcoin" with the correct path for your custom data directory)

That's normal since you've disabled "pruning". And uninstalling Bitcoin Core won't delete the data directory where the blockchain is.
Now that it's unchecked, the full blockchain will be stored in your disk but since the old blocks were pruned (deleted) before, Bitcoin core will have to re-download and verify from the pruned blocks to the tip.

Also, Bitcoin core won't automatically use the drive where it's installed as the data directory (in your case, Drive E).
You'll have to add something like datadir=E:\Bitcoin entry to your bitcoin.conf file in the default data directory which is: .../bitcoin-conf.md#configuration-file-path (read it for more info)

Pressing "ok" will start that said process.

I thought adjusting the output is part of it when you said "over-sized fit" and "(not) almost exact match" in the second paragraph.
Anyhow, the later replies further cleared what you are speaking about.

By the way, do you think my proposal of adding the dust change to the fee has better results in terms of UTXO set clutter, transaction size and possibly for privacy?
In respective order:

• if fewer txns produce change, there'll be less UTXO to save in the blockchain;
• less inputs will make smaller txns thus smaller fee;
• having one output might mislead blockchain analytics that it's "self-transfer" and having less change outputs in the wallet means less UTXO that may lead to privacy issue when used together.

I'm not going to discuss this heavily since it's not the topic here, just a suggestion for an alternative.

I think what actually fixed the main issue is when you re-download a new exe file.
The other problem that was addressed by the portable version is the stand-alone is actually using the electrum data directory in the PC where it is connected,
browsing to the wallet's directory (in your case, the copied files in the flash drive) will work but isn't "clean" since it will leave settings and other data in the PC where it's connected.

Anyways now that it works, you just have to organize the Flash Drive because having two electrum-related folders is disorganized.
The Portable version is actually using the folder "electrum_data" as the data directory.

You should copy the contents from the 'other folder' and paste-overwrite it to electrum_data folder (if the wallets doesn't have a backup, make one before doing so).
After that, if Electrum didn't find your wallet (due to wallet previously opened from the other folder), just browse to the correct folder.
Once it's good, you can now delete the other folder, your Flash Drive should only have "electrum_data" folder and "Electrum-portable.exe" file.
Now it should work to any PC plug&play as long as it can run Electrum (only use your PCs for security reasons).

Good as long as the output isn't the one that'll be changed when the change is dust unless the user specified/agreed (eg. via checkbox).
Most users will find sudden change in output amount, however small it is, a bad feature.
It's best to just add the dust to the transaction fee if it reached the "dust threshold", preset or set by the user.
With that, you should have an advanced option to set the maximum amount to be considered as dust based from the users' preference.

As hosseinimir mentioned, Electrum have a similar feature but it's only when the change is lower than the "standard" output amount which is currently 547 satoshi.
My suggestion is to implement a similar feature but the "amount" is dust or the range set be the user.