Have you sent the bug report off?
Keep note of the bug number and then follow that up with your local Archicad support people.
Sounds like it might be a problem with certain machine configurations.
Hopefully they will be able to shed some light on it.
One of the forum moderators.
Versions 6.5 to 25
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Dell Precision 3510 - i7 6820HQ @ 2.70GHz, 16GB RAM, AMD FirePro W5130M, Windows 10