I see this is covered in bug #1160 over at Github, but since I have an account here I’ll refine:
1.5.3 shows a completely white window and popups are also white. The application is actually functional, but doesn’t redraw except during resizing of the window. As soon as you stop resizing, the window goes blank again.
This is in the standard Linux container (Crostini) on an Intel-based Chromebook (Acer Spin 13), both when installed as Appimage and from debian package.