Playback speed doubles when window is on two monitors

• mpv 0.34.0-395-g9add44b11a
• Arch Linux
• compiled from source (latest master)
• KDE Plasma 5.25.4 on Wayland
• Mesa 22.1.4 using AMD R9 380

I have two 60Hz monitors and when the window overlaps both monitors, the playback speed usually (but not always) gets doubled.

In this video it doesn't happen in the beginning, but then afterwards it does two times.
I only recorded the left monitor, as that's where where most of the window is, but moving it only a little bit onto the right one already triggers it.
I've added --osd-msg1="fps \${estimated-display-fps}\njitter \${vsync-jitter}" for the video.

https://user-images.githubusercontent.com/8932183/182983850-8b972924-158f-46cb-8c15-09d2d50e285d.mp4

Note how the estimated-display-fps and vsync-jitter increase when this happens.

Reproduction steps

mpv --no-config --video-sync=display-resample https://github.com/haasn/interpolation-samples/raw/master/60.000.mkv
Also happens with local files and files with different refresh rates.
Happens with all video-sync=display-* options.

Expected behavior

Always plays video at the same speed, regardless of position

Actual behavior

Playback at 2x speed when window is on two monitors

Log file

output.txt

Sample files

haasns 60 fps test video

Start by running the reported mpv command with --video-sync=display-resample while moving the window across both monitors, and compare the estimated-display-fps and vsync-jitter values from the OSD. Use output.txt and the video-sync=display-* options as the initial context. Done means playback remains at the same speed regardless of window position, including with local files and different refresh rates.