(I tried updating to the most recent Electrum version, and it didn't work either. I think that's because according to the release notes, after 3.3.8 something changed with the Electrum partial transaction format - which I'm guessing applies to multi-sig transactions).
This only affect compatibility between the raw transactions exported by versions lower than 4.x.
So, it mainly affects Cold-Storage and MultiSig Electrum wallets that have different versions.
The issue is specific to Trezor:
https://github.com/trezor/trezor-core/blob/master/src/apps/wallet/sign_tx/signing.py#L131-L134It must have been your firmware as other have mentioned.