Tried switching between Windowed and Fullscreen/Borderless; Borderless is acting like the game is in Fullscreen and I can't even set it to Fullscreen properly, so it seems like you can't actually set it to proper Borderless. There's Windowed and then Borderless (that acts like Fullscreen) at the moment.
(For the record, Windowed is working properly, the only mode that is)