darkroom filmstrip loses marking for active image when scrolling

Is there an existing issue for this?

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

Describe the bug

The darkrooms filmstrip loses the triangle-marking of the active image when it is scrolled off to the side. See screencast.

Steps to reproduce

Go to darkroom
Have enough images in collection to fill the filmstrip + be able to scroll
Scroll the filmstrip to push the active image off the viewport
Scroll back
Observe: Triangle GONE

Expected behavior

darktable should keep all it's triangles, especially this one

Logfile | Screenshot | Screencast

https://github.com/user-attachments/assets/8b130545-1098-4338-9765-8a91fb81724e

Commit

No response

Where did you obtain darktable from?

darktable.org / GitHub release

darktable version

5.6.1 + current master

What OS are you using?

Linux

What is the version of your OS?

bazzite 41; KDE wayland

Describe your system

No response

Are you using OpenCL GPU in darktable?

Yes

If yes, what is the GPU card and driver?

RTX2060m

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

No response

Start by reproducing the issue in darkroom with enough images to scroll the filmstrip, using the supplied screencast as a reference. Trace the darkroom filmstrip behavior while scrolling away from and back to the active image; done means the active image's triangle marking remains visible after returning.