This is a known new problem. It’s first turned up in UK about six weeks ago, and after the firmware push last week it is starting to show up on US accounts. Support told me it was “trending”.
Open a support ticket.
If you like, you can also try the following: remove the battery from the presence sensor and reset it, but don’t readd it to the network yet. Then unplug the hub including removing the batteries and leave it off-line for at least 15 minutes. Then repower the hub. Then use the reset button on the hub. Then re-add the present sensor to the network. But it may only work for another 24 hours and then fail again.
Note that a present sensor which reports itself as “away” when it isn’t may just be having trouble staying connected, which is one kind of problem.
But a device which reports itself as “present” when it isn’t is an account problem. Totally different kind of issue. Because the way that the “present” status works is the device always checks in every 30 seconds and after you miss a certain number of Checkins, The account (not the fob) marks the device as away. So failing to change from present to way is an account failure. Most of the topics in the forum deal with the connection issue, not the account issue.
There are two recent topics dealing with the account level failure.