If you've created a GPS fence and you're getting wrong notifications telling you that your pet is entering on it / leaving it, it's because you're getting GPS errors. For that reason, your pet is being tracked in a wrong location, that can be outside/inside the fence by mistake, and so you'll get the alert.
In order to solve this, you could increase the size of the fence. So, even if you're pet gets tracked a few yards/meters away from its real position, it'll still be inside the fence.
Estrela's owners created a safe zone around their house. As they have a garage, everytime Estrela enters on it, she gets tracked a few yards/meters away because she's indoors (which decreases the accuracy of its position, as explained in our article about GPS errors). Given this, sometimes Estrela gets tracked outside the safe zone when she enters the garage. So, by increasing its size, Estrela's owners won't get wrong notifications even if she's tracked a few yards/meters away from her real position.