We’ve been trying to figure this problem out. From what we can tell, it’s a problem in the Qt framework that we use for all of our apps or some problem with Qt and the latest Windows 10 update.
Also, it seems to only affect Dell computers on Windows 10 (everyone who’d reported a problem is on a Dell XPS 13 or 15), and the app seems OK on a Microsoft Surface running the same OS and a similar DPI.
We’ve got some more testing to do before we go to Qt to confidently report a bug but I think the first recommendation we have is to check for updates to the video driver.
Does your XPS have the standard screen or the 4k/Hi-Dpi version?