Same bug here, Paint 11.2605.81.0 on Windows 11 25H2 (build 26200.9711). Screenshot attached, I blanked out the canvas content.
My case is the mirror of @Tycoon 's: the labels break on my laptop screen and are fine on my external monitor.
Setup:
Laptop with Intel Graphics (driver 32.0.101.8991) and NVIDIA GeForce RTX 5070 Laptop GPU (driver 32.0.16.1692)
Laptop screen: 2560x1600, normally at 150% scale, driven by the Intel GPU
External monitor: 2560x1440, normally at 100% scale, driven by the NVIDIA GPU, set as the main display
What I see with those normal scales:
Paint started on the laptop screen: everything looks normal. Dragged to the external monitor and back: now it is broken on the laptop screen.
Paint started on the external monitor, dragged to the laptop screen: normal. Back to the external monitor: normal. To the laptop screen again: broken.
Dragged back to the external monitor: normal again. On the external monitor it always looks fine.
So the first visit to the laptop screen is fine, and it breaks when the window comes back to it a second time.
All text and icons are affected. Menu and ribbon labels turn into short dashes, tool icons turn into random symbols, and the color swatches turn into colored dashes. When I tried to close Paint, the Save / Don't save / Cancel buttons showed solid bars instead of text. The first time it happened they showed round symbols, like the white circles in the question. The window layout and the image on the canvas stay correct, so only text and icons are drawn wrong.
Scale tests:
Both screens at 100%: Paint renders fine.
Both screens at 150%: fine.
Scales swapped, laptop screen at 100% and external at 150%: broken on the laptop screen again, now at 100%.
So it only happens when the two screens have different scales, and it is always the laptop screen that breaks, whatever its scale. That screen is driven by the Intel GPU and is not my main display, so my guess is that one of those two decides which side breaks. In @Tycoon 's case it was the external monitor that broke. Setting Paint's GPU preference to High performance (NVIDIA) did not help in my case.