My understanding is that you need to put your recovery seed into electrum in order for it to display your wallet. My understanding is also that if you have a trezor device, then all you need to recover your private keys is your recovery seed. Although I do not have a trezor personally so there may be an additional step required to recover access to your private keys.
I don't think this is how Electrum works with Trezor. I set my existing Trezor up with Electrum a few months ago, but from what I recall all I needed to do was create a new Trezor wallet within Electrum, and then Electrum asks for the user's passphrase or PIN, and then you can see all the balances on the Trezor accounts. So no recovery seed is needed to setup a Trezor with Electrum.
You may be using a newer version of electrum. A few months ago I was helping the OP with a problem with his trezor, was given the recovery seed and was asked for the seed to setup the electrum wallet. IIRC, I was using 1.8 or 1.9 at the time. I would need to double check if this is still the case with 2.2