Glitch when deleting areas creating using Solder Mask Expander

[Morad-T]

Create a Solder Mask Expansion
Select and Delete it
Preview of removed Solder Mask remains in PCBNew but 3D View is correct
PCBNew then seemingly randomly gets itself together, though it does crash occasionally

[Morad-T]

I spoke a little too soon
Issue #34 already better discusses this

          To add to this issue, those are the problems I encountered with this plugin in Kicad 6 (Version: 6.0.2):

• Graphical issue: after using the "Solder mask expander" tool, if you delete the generated zone, it still shows up in the editor. However, it is indeed deleted and does not appear in the renders. Reloading the GUI (for instance, quitting and relaunching the PCB editor) fixes the problem. This issue does not appear when manually creating a solder expansion zone using Kicad standard tools.
• Graphical issue: exactly the same problem with the "Trace clearance generator".
• Crash: the rounded track tool crashes the PCB editor. It is however still somewhat usable as the project can be saved, and the rounded track do not seem to crash the editor after restarting it; only immediately after using it.

This plugin is fortunately usable in Kicad 6 despite these problems, but a fix would be appreciated.

Originally posted by @CGrassin in #34 (comment)