Bug 487990

Created attachment 170116 [details]
The cursor is offscreen behind the red arrow

SUMMARY

I have a single 4K monitor setup.
I don't know the exact monitor model, but it is an LG monitor with 3840x2160 resolution.
I've noticed that since updating from Kubuntu 23.10 to Kubuntu 24.04, the bounding box of the monitor is calculated incorrectly.

On the right side of the monitor, there is weird behavior:
1. In the upper right corner until about half the screen, the bounds of the screen are insofar too large as that the cursor can completely vanish offscreen 
2. On the lower right corner, the screen suddenly gets thinner:
A few pixels of the cursor are still visible when trying your hardest to leave the screen. (attachment 2 [details])
You can especially notice that while scrolling:
If you scroll from the top down while the cursor is offscreen, you can only scroll until you reach a specific point on the y axis, at which the scroll stops and only continues once you move the cursor a few pixels to the left. (attachment 3 [details])

Notably, the bug does not occur if you are already dragging something from a visible point as then the dragging stops at the intended border. (attachment 4 [details])

EXPECTED RESULT
I cannot leave the screen with the cursor, scrolling works as expected


SOFTWARE/OS VERSIONS
Operating System: Kubuntu 24.04
KDE Plasma Version: 5.27.11
KDE Frameworks Version: 5.115.0
Qt Version: 5.15.13
Kernel Version: 6.8.0-31-generic (64-bit)
Graphics Platform: X11
Processors: 8 × Intel® Core™ i7-9700K CPU @ 3.60GHz
Memory: 15,5 GiB of RAM
Graphics Processor: NVIDIA GeForce RTX 2080 Ti/PCIe/SSE2
Manufacturer: HP
Product Name: OMEN by HP Desktop PC 880-p5xx