Nostalrius Begins - Quality wow vanilla realm (1.12)

Hello, a few days ago I started experiencing a minor, yet annoying bug, some character icons are bugged and look like this

It happens with NPC's, players, everything. Besides that everything is fine.
I tried switching off all addons, removing WTF and WDB folders, making a clean installation, deleting VirtualStore folder in /appdata/ - none of this really worked.
Any suggestions?

Past a complete uninstall/reinstall and deleting the WTF/WDB folders, I'm stumped.