I have Windows 10 and Plex HTPC. I have set Task Scheduler to open Plex on Logon. I have Plex set to Keep on top of Windows always. When the PC starts, Plex loads fine, but is out of focus. This used to work fine. Im not sure if it was a windows update or a plex update, but it no longer focuses.
This really sucks if you use a remote. You have to grab a mouse, click the screen, then it works.