I have seen this issue before, and it might be linked to the C.U.M patch. Have you tried to change the mod directory ,from the mod browser settings, to a different folder? If that doesn't work you can try and delete your setting file to fix it. you can find the file here :

Windows: %appdata%\Godot\app_userdata\Beat Banger\settings.ini

Mac: ~/Library/Application Support/Godot/app_userdata/Beat Banger/settings.ini

Linux/Steam Deck: ~/.local/share/godot/app_userdata/Beat Banger/settings.ini