Canvas.paint always firing on Windows

something strange, since Xojo 2021r1.1 on windows, i have a canvas that always fire on Windows only. That use about 20% of resource on the PC.

Any idea how to find what cause this firing (on windows)

NB : no invalidate it self in the code

DateTimePicker is the cause !

That’s odd, i can’t reproduce it in a new project…