Window contents displayed upside down while session is locked

I am experiencing a situation where the content of application windows gets displayed at moments where it should not (because there is another window on top, or, more recently, because the session is locked and the session manager’s lock screen is displayed), and with a 180° rotation.

Here is an example of the phenomenon occurring yesterday when resuming from suspend and with the session still locked. On the photography below (not a screen capture), one can see the content of Thunderbird, which is running in the session but should not be displayed at all because of session locking (note the tessellation effect was added in Gimp afterwards for privacy reasons). At the bottom where the taskbar would be present, there is no anomaly and one can see the background of the lock screen. The window that is wrongly displayed changes : the display flickers in a seemingly random pattern, displaying one window, then another. The system is responsive. Unlocking the session does not end the phenomenon, but closing the session and restarting it did.

There was an instance in the past where this occurred without a resume from suspend of session locking situation. That was then an annoyance, but the occurrence of yesterday creates privacy concerns.

The attached log may not be entirely useful, as it was generated today and the phenomenon has not occurred.
nvidia-bug-report.log.gz (425.7 KB)

Additional information : the Steam client was running at the time it happened, and its window has an habit of having display artefacts (parts of window failing to update, etc.), but they are usually confined to that particular window.

OS is KUbuntu 22.04 (up to date), with kernel 5.15.0-82-generic, KDE Plasma 5.24.7, KDE Frameworks 5.92.0, Qt 5.15.3, Xorg-server 21.1.4,
GPU is NVIDIA GeForce GTX 1650/PCIe/SSE2,
GPU driver is nvidia 525.125.06.

And here is a log taken while the problem was happening again, under similar conditions.
nvidia-bug-report.log.gz (444.7 KB)