I sent some Bitcoin to a Bitcoincash adress on Trezor and it doesn't show on my Bitcoin in Trezor, how can I get them back ?
You should upgrade your Trezor firmware. Follow the steps here: https://doc.satoshilabs.com/trezor-user/updatingfirmware.html
After it, your problem should be solved. If not, try these steps: https://blog.trezor.io/claim-bcash-bitcoin-cash-bch-bcc-trezor-wallet-f0a810d5864a