My Palemoon Snap is using the wrong theme on Plasma

IIRC, Palemoon is GTK2, right?

It’s not using the right theme from gtk-common-themes snap, and it seems to be using some super old-looking theme + my Plasma’s current color scheme.

Here’s the YAML file.

I’m getting this output repeatedly:

(pale moon:11741): GdkPixbuf-WARNING **: 13:37:47.188: Cannot open pixbuf loader module file '/usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders.cache': No such file or directory

This likely means that your installation is broken.
Try running the command
  gdk-pixbuf-query-loaders > /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders.cache
to make things work again for the time being.

My GTK theme is currently set to Yaru