Ok I was wrong about Nvidia drivers causing the remote control issue. But bear with me, I do have the definite answer.
From the beginning: Prior to the FCU, both Drivepool and Scanner were able to remote control without any issues using beta versions up to 2.2.0.870. So I updated all three devices to FCU, then Kaspersky Total Security intsalled a major update to itself I then installed Drivepool Beta 2.2.0.875. As standard practise I then created images of all three systems using Macrium Reflect.
on rebooting and leaving the devices running for a couple of hours I found that Drivepool would not remote control on any of the three devices. I posted here and worked through all of the fixes recommended by christopher and a few of my own, with no positive result.
I honestly thought it was Kaspersky to blame, but fully uninstalling this proved me wrong.
I had noticed problems with the start menu and taskbar as well by now and also sluggish performance with these systems.
So I restored all three images which I had taken just after the major update, I was now working from a known baseline. I then noticed the problem with the video drivers and all the other Nvida stuff that Windows update had installed. I removed these and re-installed the correct driver and everything was fine. Seemed very strange that this could be the cause, but hey it worked, drivepool and scanner were remote controlling fine again and the sluggishness had gone along with the taskbar and start menu problems. Worked fine until next reboot, then same problems resurfaced.
I then checked through installed updates and found that Windows had silently installed KB4043961 shortly after I had updated to FCU. This update coming into force after each system was rebooted hence
the systems working fine then the sudden problems. Uninstalling KB4043961 and further hiding it, so it does not attempt installing again, totally solves the problems with remote control, taskbar etc.
Obviously this update had sneaked in after I had created the original images of the three systems and again shortly after I had restored all systems, and incorrectly thought I had cured them with the correct video drivers.
Just this morning I thought I would google and see if anyone else had issues with this update and found the following post.
gjbth got a reaction from Christopher (Drashna) in Not able to remote control drivepool Beta 2.2.0.875