Hi everyone,   after migrating to a brand new Linux Version (Kubuntu 18.04) and Cura 4.5 appimage, I got a weird problem... Cura starts quickly and smoothly, but the upper right quarter of the window remains white and some other icons are missing also. Cura works, I can click on everything visible and get the right reactions, but not in the upper right quarter. This quarter remains, even if I downsize the whole window, it's not a problem of the screen. Also, other programs (gimp, libre