Advanced Audio Properties UI issues

[bst]

I'm running OBS 30.2.3.1 under Debian SID (Wayland/Sway window manager) and the Advanced Audio Properties UI doesn't render the checkboxes for audio tracks. I see the same issue in the Audio Track option on the Streaming Settings and Recording Settings menu.

Actually, in most themes (including the default one), no checkbox is rendered (like the 'Active Sources Only' and 'Volume %' checkboxes in the Advanced Audio Properties UI). I worked around this by installing other themes until I found one that worked (namely, Production Pro - the one in the screenshot below - and Twitch Studio), but the Audio Tracks checkboxes never worked.

I tried debugging this myself but my knowledge of QT development and of OBS Studio source code is very limited.

I'm looking for two different things, in order of priority:
1. where are the Advanced Audio Properties stored among config files? For now I'd be satisfied with simply editing config files manually to get audio tracks properly configured, while I debug the issue further. A sample snippet of the config file would also go a long way helping me figure this out. As an added bonus, pointers to (a) the Advanced Audio Properties code that sets these properties and (b) the code that writes these settings to the config file could be extremely helpful for my debug session;
2. where should I look and what should I try in order to fix these checkboxes? The fact that other checkboxes were fixed by simply switching themes tells me this should be a simple theme configuration issue that happens to not work on my particular setup.

I appreciate any help.

P.S.: Here's a screenshot of the Advanced Audio Properties UI:

 

[bst]

FWIW, I tried commenting out the background: transparent part of the default Yami theme (under /usr/share/obs/obs-studio/themes/Yami.obt) and switching to it, but that did not help.

Here's the snippet:

/* General Widgets */
/*
QLabel,
QGroupBox,
QCheckBox {
background: transparent;
}
*/

 

[bst]

Ok, I found something very interesting about this issue. The checkboxes that are displayed correctly in the Production Pro theme are backed by a PNG image. The ones that don't (both in that theme and in Yami) are backed by an SVG image.
I suspect this issue relates to QT not rendering SVG images on my system somehow.
Any pointers on how to debug this are greatly appreciated.

 

[bst]

Haven't made much progress on the issue so far. Any tips are still greatly appreciated.

For those who are encountering the same issue, the workaround I found is to convert all SVG files to PNG (imagemagick's `convert` tool can be used as `convert input.svg output.png`) and to edit *.obt and *.ovt files and replace `.svg` with `.png` (`%s/\.svg\>/.png/gc` in Vim). Not ideal, but works.