First of all Make sure you have your seed word, Passphrase could be separate for 2 different trezor as long as you have the same seedword. Currently trezor have 1.6.3 so may be you need to upgrade before proceeding which is always safe. but always upgrade with official firmware or connect your trezor with exodus which is easiest way to use and upgrade and the safest way also. Good Luck
i have only 1 trezor, but i remember that i've created two different wallet with two different passphrase.
Now it's like there is only one wallet for two passphrase!
I don't understand
How does it work the upgrade with exodus??