[Bug] Missing icons in volume mixer

[System64fumo]

Please read through the README and the Man pages before submitting
Please also make sure that there isn't any prior issue describing this bug

Describe the bug
Icons are missing in the volume mixer

To Reproduce
1: Enable show-per-app
2: Enable show-per-app-icon

Expected behavior
Icons showcasing which application the sound is coming from to appear next to the sliders

Screenshots

Desktop (please complete the following information):

• OS: Arch linux
• Version 0.9.0

Additional context
I've disabled show per app label since some programs have long names (It would be nice to have some sort of max length or something)

[ErikReider]

Is this still an issue?

[System64fumo]

I'm afraid so.
swaync 0.9.0 (git-f68dfa4, branch 'main')

[Sohail-XD]

The images were working properly a few days ago, I dont know exactly which version but they were working when the "square indicator" on the slider was added. With the latest version they do not get displayed.

[Sohail-XD]

I have to apologize but I missed a detail. Mpv, vlc icons are displayed fine. Only firefox icons don't show up.

[matthis-k]

It seems Spotify icons also don't show up.
Maybe it hast to do with the icon theme used, or something like that? I remember that being an issue in waybar a while ago and it had something to do with setting an icon theme (I think it was this module).