Everything is kind of written in the 1st post above. I tried to put many things & keep it simple at the same, to understand.
Well, from my reading, I say that it's not understandable enough. You've confused the whole situation with the given explanations. You can't have messed it up with Electrum, it's easy to use and I believe that even a newbie understands every part of the seed generation procedure. You probably made a mistake unrelated with Electrum you haven't mentioned, because you may not know it.
I tried iancoleman.io - but of course it doesn't work with Electrum wallet, since Electrum does not support BIP39. Thus everytime an Electrum mnemonic phrase is typed in, it comes back with "invalid mnemonic".
You can actually
import an electrum seed phrase in iancoleman as long as you want legacy addresses.