The TOTP code (Time-based one-time password)  is generated using the system time of the device on which the authenticator app (KeePassXC / FreeOTP) is running.
It is therefore essential that the system time is set correctly.

You can check this here: https://rz.uni-greifswald.de/wobinich/

If the system time is incorrect, please adjust the device’s system time.
In Windows 11, you can do this as follows:

1. Open Settings: Press the Windows key + i.
2. Time & Language: Select ‘Time & Language’ on the left, then ‘Date & Time’.
3. Set automatically: Ensure that ‘Set time automatically’ is set to On.
4. Synchronise: Click the ‘Synchronise now’ button under ‘Synchronise clock’.