Monitor goes to sleep then wakes back up immediately

Distribution

Linux Mint 22.1

Package version

6.4.8

Graphics hardware in use

AMD 7945HX (Radeon 610M)

Frequency

Always

Bug description

This issue happens only when the user is logged in.
It does not happen if you restart the computer and don't log in or log out.
Happens with the HDMI output and DP output (on different monitors).

When the monitor is turned off due to inactivity it will sense that there is no input and a few seconds later just before it would go into power-saving sleep mode it acts as if the computer has received input (like key press or mouse movement). The computer is locked and the password field is presented. Eventually the timeout period will be reached again and the monitor will try to go to sleep and we've entered a loop/cycle that just repeats and the computer will never reach the timeout period for suspend.

If the monitor is turned off manually the computer will eventually go into suspend, presumably because the above mentioned loop/cycle doesn't happen.

Again, this doesn't happen if a user is not logged in.

Steps to reproduce

AMD based system (Minisforum BD795i-SE) with 7945HX running LinuxMint 22.1
A user must be logged in
The "Turn off the screen when inactive for" option must not be set to "never"
Wait for the screen timeout to expire

Expected behavior

The monitor should go to sleep.

Additional information

No response

Start by reproducing on Linux Mint 22.1 with package version 6.4.8 and the AMD 7945HX/Radeon 610M setup, comparing logged-in and logged-out sessions. Investigate the screen-timeout path for the repeated wake event; done means the monitor reaches sleep after inactivity without restarting the timeout cycle.