Rescanning is something usually reserved for clients like Bitcoin Core. You don't need to rescan for Electrum.

I think you misunderstand my point about having the wrong seed and wrong file...

2 years ago, you had Wallet A with Seed A and Wallet B with Seed B... For whatever reason, you wrote down Seed B and started sending coins to address(es) in Wallet A... then you backed up Wallet B.

So now, 2 years later... you have Wallet B file with no transactions and no coins... and matching Seed B, which just regenerates your empty wallet.

However, if your current wallet has addresses that you can lookup on blockchain.info and see coins, then it could indeed some sort of network issue with Electrum. Do you have any record of old addresses that you used back when you initially sent the coins?

Under "Tools -> Network", you should see a value labelled "Blockchain"... if the number of blocks is equal to the current block height of Bitcoin Network (485020 at the time of this message) then your Electrum is sync'd OK.

If it is less than that number, then your Electrum is not synced properly. You might need to try a different server