ok, that’s not my cup of tea! 
but what I can say, if the itemtypes won’t match, you’ll see that entry in the logs.
[WARN ] [rest.core.internal.item.ItemResource] - Received HTTP POST request at ‘items/Presence_Mobile_John’ with an invalid status value ‘’.
But from what I’m reading, I guess, you’re trying to update a presence-item? there are a few threads here on how to do that, ranging from
- network-binding: Timers for on/off delay
- using tasker on Android: Another presence method - Android specific
- …