Images rendered in low resolution on 2x scaling display when 1x scaling display exists (wayland, sway)

Is there an existing issue for this?

• I checked and did not find my issue in the already reported ones

Describe the bug

When opening darktable, photos being edited are rendered in half resolution compared to the display, despite the rest of the UI being correctly rendered hidpi. This only happens when I have 1x scaling and 2x scaling displays plugged in.

Steps to reproduce

Open an image in darkroom on 2x scaling monitor.

Expected behavior

Image rendered at correct resolution

Logfile | Screenshot | Screencast

darktable.log

Here is an image showing the rendering

Commit

No response

Where did you obtain darktable from?

distro packaging

darktable version

5.4.0

What OS are you using?

Linux

What is the version of your OS?

Archlinux

Describe your system

No response

Are you using OpenCL GPU in darktable?

Yes, but it happens with opencl off

If yes, what is the GPU card and driver?

rusticl, RX 5700 XT

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

Symptoms don't disappear with resizing the window or moving it between displays or anything which would update darktable's understanding of the current resolution it should be rendering at. However, the GTK UI handles it perfectly. This has persisted for a long time, I've only just got around to reporting it. Multiple years of darktable versions, sway versions, etc.

Start by reproducing the issue in darktable 5.4.0 on Arch Linux under Sway with both 1x and 2x displays, and inspect the attached darktable.log. Compare the image rendering behavior with the GTK UI and test with OpenCL disabled. Done means images render at the correct resolution on the 2x display while the 1x display remains connected.