Apple says my MacBook password is wrong - they're wrong!

I recently migrated my old MacBook Air 2018 to a MacBook Pro 2019 using Migration Assistant. Everything transferred fine except for Apple ID.

I signed in using the correct Apple ID & password, but get the alert from Apple that I need to update Apple ID settings.

It then asks me to provide my password to unlock the new machine, the MacBook Pro, which I entered correctly.

Following that, it asks for the password on the old machine, the MacBook Air, which I also entered correctly.

However, the alert says that it has been entered incorrectly. I am 100% certain the password is correct since I just unlocked the old machine with this password. I've tried at least 10 times with the same result. None of my keychain passwords are available on Safari which I use regularly for authentication to work/ personal web apps, among other benefits of using Apple ID.

Any ideas on how to fix this?