I am running bootcamp and windows 10 on an 2017 iMac 21.5 inch with Radeon Pro560 graphics card. If I boot on the MacOS side, everything is fine. When I try to boot on the Windows side with the monitor attached, Windows chokes and won't fully boot up. If the external monitor is not attached, Windows 10 boots fine. If I hotswap the monitor to the iMac after Windows boots up, it eventually will be recognized and function. What is causing this problem? How can I fix it?