UPDATE: Apparently this is not an issue specific to remote utilities. It's affecting other remote control software platforms. I found a few suggestions but nothing concrete. I will try there with my client and let y'all know what I find.
We have a PC that when we connect the host is on the lock screen so we enter the credentials to unlock and are shown the user's desktop. Within a few seconds we are kicked back to the lock screen.
This is only happening on one PC. There are 3 others we have tried it with and they operate normally. All of the hosts are running Windows 10 and have the same set of software running. And we've tried the viewer on 2 different PCs (one Win7 and the other Win8) and both get kicked back to the lock screen so that indicates the issue is with the host PC.
About the only thing I can think of that is different with this PC is that the user has poor eyesight so it is set for a lower resolution and is using high contrast theme.