Correct password not working to unlock macbook (Yet another such an issue post)

Running MacBook Pro macOS Sonoma (don't remember the exact version)

and been experiencing a few occasion where the correct pass won't unlock the machine.

This is actually occurring right now, I can't unlock the machine despite beeing able to remote-ssh to the same machine using that same password.

The previous times this occurred, I just left the machine alone, closed the lid so it would go to sleep and then it eventually start behaving properly again.

Q1: Is the machine too busy ? (the fan is running 100% and htop on a my remote ssh-session did show Firefox and Thunderbird being quite busy(

Q2: Is the keyboard mixed up and I'm not actually typing what I believe to be typing ?

Q2a: Is there a way to force display of what's being typed ^

NOTE: I've plugged in a USB keyboard I tried again: it worked. Don't know whether it fixed itself or whether the keyboard was indeed screwed up.