Adding / removing display while locked temporarily unlocks computer without credentials

Distribution

Linux Mint Cinnamon

Package version

6.8.4

Graphics hardware in use

AMD Integrated Video (framework 16 Laptop)

Frequency

Always

Bug description

If I have my laptop locked and connected to external displays, and then remove one of the external displays (or add one), the lock screen will disappear and the desktop will be visible. Input to the desktop IS possible, and for all intents and purposes during that short duration the computer is considered unlocked. This provides enough time for a physical access attack with automated tools.

I have confirmed both that this is repeatable, and that input to the desktop is possible during.

Steps to reproduce

1.Have a computer with Linux Mint (same version as above) installed
2, ensure external monitors are plugged into the computer
3. lock the computer
4. switch one monitor to a different input (forcing the laptop to re-distribute displays)
5. Watch the main screen - observe desktop becomes visible and can be accessed during this time

Expected behavior

The lock screen stays in place, the desktop does not become visible, and it's not possible to run arbitrary code on an allegedly locked computer.

Additional information

No response

No source file or test is named. Start by reproducing the display hotplug steps while Cinnamon is locked, then trace the lock-screen and display-reconfiguration entry points involved. Done means the lock screen remains visible and desktop input or arbitrary code execution is impossible throughout display changes.