For the past few days I discovered that left click suddenly does not work on the bottom right corner region of my monitor. For some reason I decided to right click that region, and a context menu appeared, which means there is a hidden window right there. Using Process Monitor I discovered that it's QtWebEngineProcess.exe.
Process Monitor shows that it's linked to Origin.exe and sure enough End Process Tree of Origin.exe immediately shuts down QtWebProcess. Seems that if you let Origin runs for a long time in your PC, QtWebProcess will have that hidden window in your bottom right hand corner of your desktop.