Top left Hot Corner stoped working

Distribution

Manjaro

Package version

Cinnamon 6.4.2

Graphics hardware in use

Intel Corporation HD Graphics 630 + GeForce GTX 1050 Mobile

Frequency

Always

Bug description

Top left Hot Corner stopped working. Other 3 remained fully functional.

Steps to reproduce

• set up top left hot corner action,
• move mouse to top left corner of the screen.

Expected behavior

• top left corner action should trigger,
• the hot corner green wave indicator should show up.

Additional information

After further testing I have noticed that only the very top left pixel is not working. When I removed the delay from the setting for this corner, the action started to intermittently fire, often twice. It would seem the pixels other than the very top left one still trigger the action if the mouse cursor lands on them. This is unfortunately extremely unreliable due to how mouse cursors are moved in "jumps" on the screen and almost always skip over those pixels in normal use.
Adding extra monitor on top of the main screen seems to temporarily fix it.

Start by reproducing the top-left hot-corner behavior on Cinnamon 6.4.2 with the described Intel and GeForce hardware, including the delay setting and an added monitor above the main display. The issue names no source file or test, so trace the hot-corner entry point from the relevant desktop settings and compare it with the other three corners. Done means the top-left action and green-wave indicator trigger reliably.