Several factors can influence the performance and accuracy of products using satellite technology. Here is a short explanation about how your tracker determines its location thanks to the satellites, and what can affect this process.
All satellite navigation relies on satellite signals that are received outdoors. The accuracy mainly depends on the number of visible satellites. The tracker will not work indoors.
Hard surfaces (e.g. buildings around you) make the signal bounce, prolonging the time it takes to reach the device. This can result in a miscalculated position.
As long as the surrounding buildings are small you should get a good accuracy, but high buildings can be challenging and result in a less accurate position. The same could happen in a closed environment, e.g. in deep woods.
Please remember: satellite technology gives you a good indication of where your Trax is, but never solely rely on that!