On my Windows 10 machine, I noticed that I cannot use the capture region/window feature on one of my two displays. The displays are identical and I only noticed it last week. I think this was working before, but now I'm not 100% sure. What I am sure of is the fact that last week, I was able to use the feature only on display 1, today it works only on display 2. On the other display, the feature always selects the entire screen (without the Windows task bar) and does not recognize windows/regions.
I suspect this might be related to a Windows update that came in recently, but – again – I'm not 100% sure.
Windows 10, Version 1809, Build 17763.439