Strange behavior with Desktop ColorGroup

Working machine:

  • iMac retina
  • Catalina 10.15.7 in Light Mode
  • Xojo 2020R2.1

Apart from the already known bugs, it happens to me 2 to 3 times a day that the DarkMode color of dual ColorGroup is randomly set to RGB(0,0,0,0). This happens on different ColorGroups (not always the same) and for no apparent reason.

To set a dual ColorGroup: I clic on the light color, select the color, close the color picker, clic on the dark color, select the color and close the color picker. After that I work on the code, test in debug, compile and so on… Suddenly, and even without having modified a color, I realise that a color is too dark while testing my app in DakrMode. When I check this ColorGroup, the color for the DarkMode is set to 0,0,0 instead of e.g. 32,32,32! I adjust the color again and it works normally.

This happens 2-3 times a day, sometimes with the same ColorGroup, sometimes with another.
Unfortunately I have not yet found the problem and have no way to reproduce it, a bug report therefore seems unnecessary at this stage. In the meantime I returned to my own solution to manage colors and no longer use ColorGroup but I wish this problem could be fixed.

Has anyone seen this phenomenon as well and if so what can be the cause?