what could be causing this?

LillyanFadzi​ That's a broken UI-affecting mod. 

Please start at the pinned Broken and Updated Mods and CC list, which you can also follow for notifications of new information. And see the part in How to Use Mods and CC about managing your mods when the game has an update, and about how to test your Mods folder (vanilla and 50-50 testing).

LillyanFadzi​ if you use uicheats mod it is likely that one there is a new version.