Pointer movement causes apps to slide out of VDU view

I use a laptop with Windows 10 and MS Office applications, and extend the display area to two additional VDUs (VDU 2, VDU 3). If I display an app (e.g. Excel, Adobe Reader) on VDU 2 in near-full-screen view, and move my mouse pointer quickly toward the lower portion of the display area, the app will slide upwards (automatically) so that the upper section of the displayed app (including the header/menu ribbon area) will be out of view. I have to 'bounce' the mouse pointer against the upper boundary of that VDU display area to get the app to creep back down into full, original view. I don't want

Question by HappyZappy on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.