Sometimes, in what seems to be for an unpredictable reason, when moving the pointer by mouse toward the big + sign on the top line of an individual window, the main window (I bet they have better terminology at RM home) pops up from behind the individual window. The individual’s window does not go away, so I just need to click on it and go on. So this behavior is annoying but not destructive, but it does break my concentration on useful work.
If I knew when this was going to happen, I probably would avoid it.
If this is a feature rather than a bug in the user interface, I would like to know what the designer had in mind.