PagePanel transparency on Windows

Xojo 2019 R1 - I can’t get the transparency property to be recognised on Windows. Could anyone shed a light?

Did a quick test, you can get the project here.

As you can see, transparency of the pagepanel works. (2019R1.1)

Thank you. That worked. I had a coloured rectangle under the PagePanel. That didn’t work. This gives me a workaround.

check if the controls set correct parent in designer.
should see as red recangle line around.