I just installed HODL wallet to see how it works. (I had to use a phone with an old version of android, since it was not compatible with a newer version of android.)

The seed phrase generated by HODL wallet is BIP39. So, if you entered the seed phrase correctly and checked "BIP39 seed" option, it should allow you to click on "Next" button.
The error you got means that you entered the seed phrase incorrectly. Check to see if you have made any typos.

If your transaction has been flagged as RBF, you should be able to increase the fee with electrum easily.
I haven't ever used HODL wallet, but since they suggested increasing the fee using electrum, I assume it automatically flags transactions as RBF.

Did their support tell you what derivation path you should use for recovering your wallet?
I created a wallet on HODL wallet and imported the seed phrase generated by it in electrum and got different addresses.

Edit:
According to their github, HODL wallet uses the derivation path of m/0' and that's what you should enter as derivation path when recovering your wallet from seed phrase.

What version of electrum are you using on your mobile phone?
As I said in my previous post, there was a bug in the version 4.4.3 which caused the "next" button not to work when generating a new seed phrase and entering that for confirmation and that was solved in the next release.
There was no bug when entering the seed phrase for recovering the wallet.


It shouldn't be like this. You definitely did something wrong.
If you have generated two seed phrases in trustwallet, you should be able to import both of them in electrum. This is assuming you have selected "BIP39" option.


Right. That's how seed phrases generated by electrum work. There's a version number that has been encoded in electrum seed phrases and makes any seed phrase generates only one type of addresses.
Unlike an electrum's seed phrase, a BIP39 seed phrase can generate different type of addresses.

This doesn't always work.
You can know the type of an address starting with 3 with decoding a transaction made from that.
If there's no outgoing transaction from the address starting from 3, there is no way to know the address type and block explorers can't display such information about the address.

This can't be the problem. OP is probably entering a wrong seed phrase or entering a BIP39 seed phrase without selecting "BIP39" option.

The bug you are talking about appeared in the version 4.4.3 when confirming the seed phrase after generating a new one
There was no bug when entering the seed phrase for recovering the wallet.

Take note that mempool is like a waiting room which nodes keep unconfirmed transactions there.
Mempool.space which was suggested above is a service that you can use for fee estimation. Mempool.space is also a block explorer.

Segwit refers to addresses starting with bc1 or 3*.

With using segwit addresses, you can pay less fee.
Addresses starting with bc1 are called native segwit and addresses starting with 3 are called nested segwit. It may worth mentioning that with using native segwit addresses and nested segwit addresses, you can decrease the transaction fee up to 53% and 38% respectively.

*Not all addresses that start with 3 are segwit.


To be more accurate:
The transaction with higher fee rate will be confirmed faster, even if the the transaction with lower fee rate has been broadcasted earlier.

The time a transaction has been broadcasted doesn't matter at all. All matters to mines in the fee rate, so that they maximize their profit.
The transaction paying higher fee rate has bigger chance to be included in the blockchain even if the transaction paying lower fee rate has been made much earlier. Miners prioritize transactions based on their fee rate and don't pay any attention to the time they have entered the mempool.

Posts are sorted correctly. It's the time displayed on your image that is wrong.
For example, NotATether's post has been made on September 19, 2023, 10:45:22 AM (UTC), not Today at 10:45:22 AM.

Check the first page of thread once again and if the times are not shown correctly, do a hard refresh (CTRL+F5). It seems that you are seeing an old version of the webpage.

It has been always like this.
You have been always able to use any address you want for receiving the change. The change address can be the address you send the fund from or it can be a different address.

Take note that whether the change is sent to a new address or the same address, it doesn't make any change to transaction fee.
When it comes to transaction fees, it doesn't matter whether you have received 100 UTXOs on a single address or the 100 UTXOs on 100 different addresses.


Let me explain how reusing an address can harm people's privacy.

Assume that I have received some fund from person A and now person B wants to send me some fund.
If I give the person B the same address as the one I gave to person A, person B can know how much bitcoin I have received before.
If I give the person B a new address, there is no way for him/her to check my previous transactions.


Again, it doesn't any change to transaction fee.
Transaction fee depends on number of inputs and outputs. It doesn't the number of addresses that determines the transaction fee.

Whether it's the desktop version or the mobile version, if your seed phrase is correct, you should be able to import your wallet.
Both mobile version and desktop version should generate the same addresses.

Where did you generate your seed phrase?
If your seed phrase has not been generated by electrum, it's probably BIP39 and you must check "BIP39" when recovering your wallet on electrum.


Take note that passphrase is different from password.
If you have extended your seed phrase with a passphrase, you need that whenever you want to recover your wallet from seed phrase. As mentioned by pooya87, passphrase is also known as 13th word.
If you have encrypted your wallet with a password, it only encrypts your wallet file locally and you don't need that when recovering your wallet from seed phrase.


You did the right thing.
It's always recommended to download electrum from its official website.


It's not recommended to use web tools for generating keys.

And what do you mean by offline?
If you just disconnected your device from internet when generating the keys, you didn't really increase your security. You should use an air-gapped device.


No.
Electrum (which is one of the safest wallets) is open-source and its code has been reviewed by many people.
You can be sure that electrum generates the seed phrase randomly and you are the only one who has access to the seed phrase (This is assuming you are not using a fake version of electrum and your device is not compromised.)

To add to o_e_l_e_o's post:

Electrum is open source and the algorithm it uses for deriving private keys from the seed phrase is available to the public. The private keys are derived from your seed phrase locally on your own device and you don't rely on any third parties for that.
Even if electrum developers abandon the project and their website is shut down, you will be still able to derive your private keys from your seed phrase.

Right. If your seed phrase has been generated by electrum, it's not BIP39.

There is no need to go for an old version of electrum. You can use a new version of electrum. It's compatible with your seed phrase.

If you worry about security of your computer, you should buy a new one or format your hard drive and reinstall your operating system.
It may worth mentioning that you don't have to import your seed phrase into an online device. Electrum allow you to sign transactions offline.

As mentioned above by LoyceV, you can use TOR browser whenever you want to check your addresses balance or a transaction on block explorers.
And to protect your privacy better, you can use a new TOR circuit every time you want to check an address or a transaction on a block explorer.

You can also run your own node, so that you have a full copy of the blockchain and unconfirmed transaction. In this way, you can check any transaction or address without relying on any third parties.


You are right about electrum, but we don't know whether OP is using electrum or another wallet.

With using a block explorer, you reveal your IP address to them. If you enter your address in a block explorer and they share such information with chain analysis companies, it may helpful to be used for tracking you, especially if you enter your address many times and you use different block explorers.

Checking the balance of an address on a block explorer doesn't mean you own that address, but it may give some hint to chain analysis companies.

You can check your transaction on block explorers, so that you get information about that from different nodes.

It's possible that the node your wallet is connected to is not synced and you want to get information from other nodes.
It's possible that the node your wallets is connected to has dropped your transaction from its mempool for some reason and you want to know whether other nodes have done the same thing or they still have your transaction in their mempool.

If I have received a transaction and it doesn't show in my wallet, the first thing I will do is check the transaction in block explorers (This is assuming I don't care about my privacy).

Old blocks (the blocks mined before the hard fork) are not separated from the blockchain. We will still have the old blocks in the blockchain.
Those who agree with the hard fork and support that upgrade their software and those who don't agree with the hard fork are free to continue with the old rules and have their own chain. Blocks mined before the hard fork would be same for both groups.

Cashapp is the receiver, not the sender. Cancelation (which actually means replacing the transaction with a new one paying higher fee) must be done by the sender.
The only thing Cashpp can do is CPFP, but they won't do that.

And the 2 weeks period you are referring to is the default time that nodes drop the transactions if they stay unconfirmed. Unconfirmed transactions can be cancelled (replaced by a new one) by the sender at any time.

It wouldn't.
You can't use ViaBTC free accelerator if your transaction size is greater than 500 bytes.
OP's transaction size is 630 bytes.


So forget about CPFP.
Since Cashapp is a custodial service and you have no control over the private key of the receiving address, there is no way to do CPFP.

Where did you send the fund from?
If you have the private key of the sending addresses, you can replace the transaction with a new one paying higher fee. Of course, as your transaction has not been flagged as RBF, that wouldn't be easy.

Where does the receiving address belong to?
Does it belong to a custodial service like a centralized exchange or a non-custodial wallet?
If you have control over the receiving address (means that you have its private key), you can do CPFP.

CPFP (child pay for parent) means that you spend the unconfirmed output in a transaction with high transaction fee, so that a miner include both transactions in the same block.
If you have full control over the receiving address, but your wallet doesn't allow you to spend unconfirmed outputs, you should import your private key (or your seed phrase) in a wallet allowing you to do so.

The transaction will remain unconfirmed and nodes will have it in their mempool until the network becomes less congested, so that its fee rate is enough and it gets confirmed.
 
It's also possible that nodes drop the transaction due to their mempool reaching its maximum size.
If a node reaches its maximum size, it would remove transactions with low fee rate, so there's room for transactions with higher fee rates. The default mempool size is 300 MB.

The other possibility is that the sender makes a new transaction with the same input(s) and invalidates the unconfirmed transaction.

I think the transactions have been rebroadcasted several times and that have caused many nodes to still have them in their mempool.

Blockchair.com received one of the transactions on September 4 and the other one on September 6.
Trezor explorer received the transactions 3 days ago. Viawallet explorer received them 2 days ago and bitcoinblockexplorers received them just a few hours ago.