Here is a screenshot:
As you can see, the white is from another window (in this case Firefox).
I changed "Options->Advanced->Transparency type" to "Region" (the one I actually didn't try yet) and the problem seems to be solved but now the "To Do" list and "Agenda" are turned to black (so lost all transparency).
The situation appears to be:
- when choosing option "Copy" or "Native", the screen holds remnants of other screens, leading to this:
- when choosing option "Region" no problems with intertwining windows but the two other windows are turned black (if you wish, I can send you an example of that too).