Communication is indeed the key.
Excellent post from Petra.
Let me add that no matter how honest and professional you are, Upwork's time-tracking software and back-end quality control systems do not know how to handle you, as a contractor, honestly doing work off the computer while running the time-tracker.
If your work entails long periods of inactivity, I strongly advise you to use manual time, rather than the time-tracking software. Because Upwork has automated algorithms that might flag your behaviour as fraudulent and your account could be suspended. Yes, even though you were doing nothing wrong. Or maybe that won't happen to you. For me, it's too big a risk.
I sometimes do work that doesn't involve work on the computer, such as when I do consultations by phone. When I do that, I use manual time. I don't just start the time-tracking software and leave it running.
My advice, don't worry too much about it.
I just hired my first freelancer on Upwork a couple of days ago.
I never even bothered to look at his work diary....Why?
He does good work, and I am happy....
As long as the hours are in the ballpark area of what I think it should cost, then I don't care...
Additionally, I feel like a bit of a "peeping tom" looking at snaphsots of someone else's computer screen..
WorkDiary is a little creepy IMO..
If there is no activity the tracker will log you out automatically.
I found this out doing a job where I had to watch a video first before doing anything and kept getting logged out.
CS suggested that I press a key every now and then to avoid this.
So I'm not sure how there can be long periods logged in without any activity.