There is an empty select item in the preferences dialog, not sure what was there before. I guess it was the graphics driver select.
I get this at startup:
Qt warning: QT_OPENGL=angle is no longer supported in Qt 6
Qt warning: Invalid value set for QT_OPENGL : "angle"
Thats a bummer, because using angle was the only thing which helped with the memory leak issues
described in
Solution that worked was in this thread:
https://forums.ankiweb.net/t/ram-usage-goes-up-with-each-review-leading-to-slowdown
A quick test shows that resizing the main or add window now eats up my RAM again and never releases it.