thanks for the hint! I just need to modify 2 lines and it works with electrum
"seed mnemonic" 
do you think this would also be the case for RDH40's problem? did he ever say anything about pairing Ledger+Electrum?
his seed mnemonic might have been generated by electrum, which might also be a valid BIP39 Mnemonic phrase
so when he tried it on iancoleman's page it gives out the BIP39 version instead of Electrum version