There was a bug with python-trezor and they say it is fixed, check here : https://github.com/spesmilo/electrum/issues/5006

Since I am not use Trezor, and never have anything similar with Nano S in combination with Electrum, can not help you more. I guess pyton need to be updated so check this link for more info:

https://github.com/trezor/python-trezor