Tried another 2 things:1) Attached an 27-inch monitor to my T410 with 2560x1440 resolution. Still garbled, so, it's not related to low(er) resolution. (The 27-inch is that one that is attached to my core-i3-8100-machine. Standard resolution on my Thinkpad T410 is 1440x900, the T530's reso is 1920x1080.)
2) 0.19.1 App-Image from freecadweb.org works with no (graphical) problem, so far.
Greets!
