I do confirm that the bug is present now in the cura package (v. 3.3.1) and makes the software unusable.
This has been reported to Cura developers: https://github.com/Ultimaker/Cura/issues/6841 It is not related to video card (it does not work with modern intel or nvidia). Using Debian 10, 4.19.0-13-amd64 #1 SMP Debian 4.19.160-2 (2020-11-28) x86_64 GNU/Linux Thank you, Riccardo
