Hmm, weird. Can you take screenshot?
Well, as I started the game up to do so (even though I restarted several times before), and it decided to display them correctly. *shrug*
Aha! If I start the game using OpenGL as preferred renderer, it happens. OpenGL ES works fine, so does Softpoly and Vulkan.
Thank you! I'll just warn people not to use it with OpenGL renderer then.