In Things about Windows 10 #2 I wrote:
It turns out Windows 10 is fairly terrible at remembering window sizes and placement when connecting to or disconnecting from an external display.
This post is in a similar vein.
The Windows 10 taskbar houses a few apps that constantly run such as OneDrive, Google Drive, Docker, 1Password, etc. This is very similar to macOS's menu bar at the top of the screen. These small apps don't require full window interfaces in many cases, and they run all the time, so the developers decided not to make them full blown apps that have their own task bar items with other apps like your email or calendar.
The issue I have is that whenever I change display sizes the "faux windows" or small pop-up dialogs that these icons invoke all but disappear (see right side of screenshot). From my research and my own noodling around there is no way to retrieve these without restarting the processes these icons represent. It isn't as easy as quitting the "app" since you cannot find the interface to do so. You have to open the Windows 10 Task Manager and find the process and quit it. Then reopen that process yourself.
I waited several builds of Windows 10 to write this post, thinking it would be fixed very quickly. I cannot imagine that Microsoft's Windows team isn't running into this every single day themselves so I'm hoping a fix is in the works.