That did work but it's a weird workaround. I have it at 125% because 1440p monitor at 100% text is super small. Thanks for identifying the fix!I had the same problem, but... I kinda forgot how I fixed it ^^". Did you have the text size of windows configured to a value other than 100%? If you do, try to change it back to 100%. That setting is responsible for bugs like that in other games. Anyway, you can find that in the display settings (right-click on the desktop, is one of the last options).
Edited: Oh! I just remembered, I think it was the configuration in the file "Game.ini". I'm using the config below now, and it's working fine here. But you may need to test other combinations for those values:
[Fullscreen++]
Fullscreen=1
FullscreenRatio=0
WindowedRatio=1