So for a while now Ive been having the issue of broken QT Apps running on gnome when not a flatpak. This would cause the applications to be mostly white and unusable, so i finally went about figuring a way to fix it. If you have this issue try this. I couldnt get qgnomeplatform to work with this and had to swap to kvantum.
Well in my case with qgnomeplatform the only functional QT application i had was obs-studio but it had some really bizarre theme issues. This was the only thing that fixed it for me outside of being forced to use flatpaks for anything QT.
EDIT: now that i think about it i believe it began with the introduction of libadwaita
Edit2: This was similar to my issue except everything but the 2 video previews and a couple buttons was white when using qgnomeplatofm
I’m giving up on trying to make anything look consistent in GNOME! IMO the GNOME developers have won! The have finally threw enough obstacles in front of me to make me give up on theming “their” DE. I’m able to get a consistent look and feel between GTK and QT applications in Plasma in under a few minutes. I’ve been fighting with GNOME 42 all day today! I can’t even get some GTK applications to look right with other GTK applications in GNOME, let alone QT applications. IMO theming is dead in GNOME! If you don’t like the GNOME defaults, you are out of luck!