Version 18.104.22.168 for both host and viewer. If I leave the viewer idle for a while and return to it, I can still see the host computer but no actions I take have any effect. I have to log out and log in again. I've checked my logs, and don't see any errors, just me logging off and back on repeatedly. Program is recently installed (i.e. I've never not had this problem).
I'm grateful for your help. Taking your questions in turn:
When the program "freezes", I can move around the screen but no actions I take have any effect. I have tried, certainly, for 20 seconds or more. Also, I can tell by looking at my Outlook inbox (or, I guess, a clock) approximately when the freeze happened, because beyond that time I won't have any new emails.
The manual pause feature works, and when engaged produces a result exactly like what I'm talking about. Also, maybe a hint, or maybe another problem, even when the viewer is working, a lot of times clicking on the outlook icon won't restore the outlook inbox. Instead, I have to right click on outlook in the the program manager and click on "Bring To Front".