I just noticed something strange, a difference between the way GTK2 and Qt5 panels work.
I have a form that serves two purposes, only difference is some controls at the top. So, I have two panels, one partially overlaying the other. The upper panel may, or may not be visible.
But I find I can see labels on the lower panel even when the upper panel is visible.
Attached image show the text of the two panels mixed together. This does not happen with GTK2 (nor, I think, Windows/MacOS). Is this intentional ?
Davo