Missing Finder Windows

[ulf01]

I have an issue with Finder and apparently also with other applications:

I frequently experience that Finder windows don't show up, they get lost. Finder lists them in the Window menu but I can not make them visible.
Selecting Window/Bring all to front results in nothing.
Clicking on "Show all Windows" (Finder Icon in the Dock) results in "No Available Windows".

I am working with a MacBook pro and a second, external screen. The missing windows can be found on both screens on none of the available desktops. Unplugging the second screen does not help.

This happens practically daily during normal office work.
My solution is certainly to open one more new window. But what is the reason for this issue?

 

[barbu]

Yes I have seen this as well, while using my USB-C startech dock. Luckily there is a solution:
open System Prefs, then Displays. The Display control panel has a button at lower right called "Gather Windows". I think that's what you're looking for.
I don't know why the problem happens as the logic of how the system reacts when a whole patch of desktop real estate suddenly disappears, but it must be complicated.