Same annoying issue here on Windows 10 x64 1803 with all updates until now!
The issue appears on several apps (chrome, IE, eagle, ...) so it does'nt depends on the app.
My setup is: 2x HDMI/DVI 24" Monitors on an Radeon HD 5450. Internal Intel GPU is not used.
The issue just happend recently sind a few weeks.
I have found an workaround which helps at least for me:
* Open Task Manager
* Goto Tab Details
* select dwm.exe and click "Kill Proccess"
dwm.exe will be closed and restarted automatically from windows and issue is gone.
Yeah i'll know, its a rather annoying workaround but the quickest for me until a real solution pops up.
In my work notebook the problem started to occur months ago but I couldn't identify what exactly caused the problem.
Today my home computer started to present the problem exactly when I right-clicked on a .PDF file, selected "Open with" and then selected the "WORD" application.
At the same time my "E-MAIL" (native application of windows 10) that was open in the background started to present the problem and when opening a new CHROME window, it also presented the problem.
Detail that on that occasion all those applications that presented the problem opened / were open on my main monitor, while on the secondary monitor I had an open CHROME and the problem did not occur on it (at least so far).