Your wallet is just a tool for you to spend your Bitcoins. You can have multiple wallets on different computers but you'll never be able to spend the funds twice.
If the addresses generated on mycelium and Electrum differs from each other and you still see the same transactions on both wallets, that is not possible.
Yes, now I see it's not the same address, its just showing up that the funds are being received on that address and it is showing total balance in the electrum.
I saw the double spend thingy already. If I send fund from Mycelium then that is also in the outgoing transaction on electrum. It was crazy to see when I realised my mistake for the first time. I thought my wallet was literally hacked. Lolz.
I'm not sure which part you are misunderstanding but let me explain how things work.
The "recovery phrase" also known as seed phrase is used by HD wallets to derive your keys. Your wallet is going to store these keys. If you generate the seed phrase on Electrum then import the same thing in another wallet that supports Electrum algorithm, you WILL get the same keys (so same addresses) from it.
You can do this offline, online, on another machine, using another wallet, etc. You should always get the same set of keys. That is the whole point of Hierarchical Deterministic wallets.
Keep in mind that it is not safe to re-use the same seed phrase on more than one device using different wallets. Try to generate a new seed phrase on the other wallet (Mycelium), this way you don't risk losing your funds in case there were any bugs in the other wallet that could reveal your keys.
I get it now. Recovery phrase is the whole thing here. I think I should move all the funds to whole new address and start over.
No way Im using the current recovery phrase since ti will give access to both the wallet and putting everything at risk.
That is the whole point of Hierarchical Deterministic wallets.
Im gonna read this now. It's a new learning for me.