I understood why this worked. Simply, when rebooting, the fingerprint unlock stops working.I found a workaround for fingerprint unlock not working, if you are rooted.
Usually, after a reboot, fingerprint unlock doesn't work. If so, flash a module (every one, even reflash one of yours) and reboot.
The fingerprint unlock will now work. Until next reboot...
But if you turn your phone off then on, the fingerprint is ok. I don't know what's the difference, but this is the behaviour.
Now, the only oher issue is that some system apps are ccrashing. I usually don't get mobile signal after these crash, so I think this can be related to the updated baseband for vulnerabilities.
I'll try to flash a different baseband and see what happens.