Re: Electrum 4.0.2 imported wallet from Bitcoin Core, cannot send BTC cannot get key
The old wallet use address that is completely different but starts with 1 still. And that addresses public key is not same and cannot be checked from check private key. If Bitcoin core addresses start usual from 1 and have some letters, most of the Electrum addresses i got start from 129 - 126 - 114 etc in the begining of address
If you only imported 5 keys, then you should only have 5 addresses in Electrum. If you have more than this, then it sounds like your wallet file might be corrupt? 
Which addresses did you send the funds to? Do you still have these addresses in your Bitcoin Core?