Using fractional scaling to compensate for different monitor DPI breaks wallpaper

[i-am-gizm0]

Distribution

Mint 21.3

Package version

6.0.4

Graphics hardware in use

Intel Iris Plus Graphics G7 (i915 driver). Detachable dGPU: NVIDIA GeForce GTX 1660 Ti

Frequency

Always

Bug description

I typically use my laptop with two monitors: the built in one (approximately 4K) and an external 1080p display. I use fractional scaling to set a different scaling factor per monitor (built-in at 200% and external at 100%). This usually causes the desktop wallpaper to go black. Once, it didn't completely go black and the wallpaper got shifted around strangely instead (caused it to span both monitors and was misaligned with black bars on one side on each display).

Steps to reproduce

Connect two monitors with different DPIs to the system.
Enable fractional scaling (beware the weirdness that already comes with that).
Set a different scaling factor for one monitor.
Desktop wallpaper goes black or gets shifted.

Expected behavior

Wallpaper properly refits to each screen as normal.

Additional information

I am using a Microsoft Surface Book with the linux-surface 6.8.8 kernel.

inxi -G
Graphics:
Device-1: Intel Iris Plus Graphics G7 driver: i915 v: kernel
Display: wayland server: X.Org v: 1.22.1.1 with: Xwayland v: 22.1.1
driver: X: loaded: modesetting unloaded: fbdev,vesa gpu: i915 resolution:
1: 1616x108060Hz 2: 1920x108060Hz
OpenGL: renderer: Mesa Intel Iris Plus Graphics (ICL GT2)
v: 4.6 Mesa 23.2.1-1ubuntu3.1~22.04.2

[i-am-gizm0]

I noticed today that this problem still occurs without the second monitor connected with fractional scaling enabling.