Yes I believe it’s only when the device is idle for a period of time.
A couple months ago I just set up a virtual presence for his iPhone 6s and my iPhone 8. I’m only using his presence for my goodnight routine to see if I should leave the downstairs lights on or not, so nothing critical. It’s turned all the lights off on him a couple of times and I had to go up to 90 minutes of timeouts on his phone to make sure I don’t get a false ‘not present’
After making this change I set it down to 5
and actually I just got a not present in the device events that lasted for one minute. I don’t see the cause for it in the logs - A little more debugging but this looks promising.
Edit: nope i was wrong - that was my weekly wifi reboot @ 3:15am on Tuesdays.