Bizarre Window Behavior

In my desktop application, I have a Movable Modal Window with several Text Fields and Labels. When I run the application and open the window a strange event occurs. As I tab through the Text Fields, the Labels darken (get bolder), and they continue to get even darker as I continue to tab through the Fields.
I have no code (that I know of) that would affect the labels in this window. Any ideas as to what may cause this?

See:

https://forum.xojo.com/37610-labels-overwriting-without-erasing/0

Thank you Jeff. Setting the label’s Transparent Property to False (Off) fixes the issue. Still, very odd. Is this a bug?

Sure seems like it. These already a couple of feedback reports (in Jeff’s link)