[HELP] Dark mode not working in GTK4 apps (like Nautilus) on Gnome 46

I am absolutely stumped and hoping someone can help me. I'm on Gnome 46, kernel 6.8, Mesa 24

When running in Wayland, dark mode works without any issue. But unfortunately, xwayland is throwing up some issues with resized game windows and mouse captures only working in the upper left quadrant of the screen. So I switched over to "Gnome on Xorg".

Dark mode works for apps like Firefox, but none of my GTK4 apps change from light-to-dark.

I've reset my dconf using dconf reset -f /org/gnome/ and I've deleted gtk-4.0, gtk-3.0 folders from .config, I've tried to delete every file or folder in .config .local that may interfere with this, but no luck.

Over on Reddit, someone recommended installing gnome-themes-extra which has been installed on my system for a long while. Reinstalled, but made no difference.

I created a separate user and logged in. Everything works without a problem (X11 or Wayland). So there's definitely something in my current user folder not working.

The bizarre thing is that once I log back into my main user, after logging in as the other temp user, things work and I can switch between light and dark mode without a problem.

If anyone could help, I would be so, so very grateful! I'm reaching the point where I think I should just nuke my user folder and start from scratch, but since I don't know where the issue is lurking, I don't want to lose all my settings either, nor copy them over...