At the moment you are too greedy :). The logic inside the Homey app can’t handle that scenario.
At the moment that you are crossing the border, the phone app tells the Homey app that it is leaving a fence and/or entering one.
But it is an interesting scenario. It is worth some debugging. Could you give me some logging from the Homey app. First i am interested in the _location messages. If you are in your town and home, what does the inregions section in that message say. Does it have two entries (home, town)?