Buggy TOTP - fixing?
im not sure its an app fault or an implementaion fault.
If you use an opensource app like andOTP and backup your secret key and then later restore it, the TOTP function is broken.
On both times the time is correct on the device.
If you use an other device its the same - the onetime pw isnt correct.
Nitrokey pro cant add your secret key (TOTP) - it wants it in base 32 im not sure but i guess you use a sha function?
I was not able to reproduce the described behaviour with andOTP. I created an encrypted backup, restored it and was able to authenticate with Tutanota.
The TOTP key of Tutanota is Base32.