If Trezor Suite opens an empty wallet after you enter a passphrase, check the spelling before assuming the funds are gone.

With Trezor's existing passphrase feature, the wallet backup and passphrase together determine which wallet opens. A capital letter or an extra space opens a different wallet. Entering that typo doesn't move funds out of the original one.

There is another check worth making: Settings → Networks. Suite reports a wallet as empty when it finds no balance or transaction history on the enabled networks. The correct passphrase can still look unhelpful if the network holding your funds isn't enabled.

Use the same wallet backup, reproduce the exact passphrase, and enable the relevant network. Trezor's guide distinguishes this empty-wallet situation from a “Passphrase is incorrect” error during signing or address verification.

If the passphrase is genuinely lost, Trezor cannot look it up or reset it. The backup alone won't restore that passphrase wallet.

Source: https://trezor.io/support/troubleshooting/trezor-suite-issues/fix-passphrase-wallet-problems-in-trezor-suite