Created attachment 143347 [details]
screenshot

SUMMARY

I have two monitor, one is rotated and scaled down (95%). When I maximize an app on that screen, it is using the bottom limit from the right monitor. I'll attach a screenshot. I'm using wayland.

Zooming in the border, I could see that the right painel is about 1px over the left screen.
The panel was expanded using the painel config ("maximize the painel")

My kscreen conf:

[
    {
        "enabled": true,
        "id": "eeee47da3181b6cbbae6d1472241e6f8",
        "metadata": {
            "fullname": "xrandr-Hewlett Packard-HP L190hb-BRG11407Q8",
            "name": "Hewlett Packard HP L190hb/BRG11407Q8"
        },
        "mode": {
            "refresh": 59.887001037597656,
            "size": {
                "height": 900,
                "width": 1440
            }
        },
        "overscan": 50,
        "pos": {
            "x": 0,
            "y": 0
        },
        "primary": false,
        "rgbrange": 0,
        "rotation": 2,
        "scale": 0.9492,
        "vrrpolicy": 0
    },
    {
        "enabled": true,
        "id": "9c25045418948794054c3d2d64ad8519",
        "metadata": {
            "fullname": "xrandr-2470W-E8562IA000190",
            "name": "AOC 2470W/E8562IA00019"
        },
        "mode": {
            "refresh": 60,
            "size": {
                "height": 1080,
                "width": 1920
            }
        },
        "overscan": 0,
        "pos": {
            "x": 947,
            "y": 218
        },
        "primary": true,
        "rgbrange": 0,
        "rotation": 1,
        "scale": 1,
        "vrrpolicy": 0
    }
]

It might be a rounding error (because of the scale)

Linux/KDE Plasma: Linux OpenSUSE Tumbleweed 20211106.