P.s. Since you have imported your seed into electrum, regard it as compromised.
You should reset your nano s and reinitialize it with a new seed, which you should NEVER enter anywhere except the nano s itself.
The nano s stores the seed securely and non-reachable. By importing it into a desktop wallet you are defeating the whole purpose of a hardware wallet.
This is correct. Your seed is already compromised.
Electrum supports ledger nano wallet, but it is not supposed to be used in that way.
There is an option for hardware wallet in Electrum options
https://support.ledger.com/hc/en-us/articles/115005161925-Set-up-and-use-ElectrumHi, I imported a bip39 seed to electrum which contains multiple btc adresses with balance, but electrum wallet only shows 1 adress with balance. Anyone knows why?
Probably happening because you have addresses in different derivation paths. Try m/49/0/0
Also, you may have change addresses. However, hardware wallet + electrum are not supposed to be used in that way.