What do you need to understand first?
This is different from a screen lock or application password. Under the recovery-phrase standard, a different passphrase can produce a different wallet rather than an incorrect-password warning. Use only a setup whose behaviour and recovery instructions you understand.
What might this look like?
You restore the recorded words but see an unfamiliar empty wallet. The missing piece might be the exact extra passphrase, rather than missing funds. Guessing or repeatedly changing the setup is not a substitute for knowing what you originally used.
Where is the safety checkpoint?
How can you work through it?
Identify the feature
Check whether your wallet uses an extra recovery passphrase. Do not infer it from a prompt labelled password.
Understand exact recovery
Read how the wallet handles spaces, characters and entry. A small typing difference can change the result.
Plan for loss as well as theft
Protect the passphrase while ensuring your own recovery does not depend on memory alone. Think through what happens if either record is unavailable.
Check the complete setup
Use the documented safe check with all required information. Keep the working wallet while resolving any mismatch.
When should you pause?
If the extra secret makes your plan too hard to recover, pause before enabling it. Added complexity is a responsibility, rather than a guarantee of safety.