Composition mode duplication, empty tab accumulation

Frequently (but not always) when I enter composition mode, when I alt-tab to switch between windows I’m shown 2 windows for the composition screen. I can work on either fine without issue. But once I exit out of composition mode there is an empty tab that remains behind and that I cannot exit out of, and that does not show up on my task manager as a process I can end once I’ve closed out of Scrivener. The main problem is that these empty tabs accumulate, which makes it increasingly difficult to navigate through windows of multiple applications, and the only way to get rid of them is to restart my computer.