Another user found out that his problem was the Passphrase feature. Basically, the state it was in when you created your wallet on Metamask. So you can try this and see if you have the same issue:
If you had enabled the Passphrase feature in Trezor when you created the Trezor connected wallet there, you must have this feature enabled later to see your funds - regardless if you use the feature or not.
Vise versa, if you didn’t have the Passphrase feature enabled when you created the Trezor connected wallet on Metamask, then you must have this feature disabled to see your funds on Metamask.
I’ll have to add that I’ve not tried this myself so I can’t say if it’s going to work, but it’s worth a try.