If there are receivers nearby the device, they will interfere with the GPS signals. We all know the GPS satellite signals can be blocked by walls or concrete. Outside, when the device has a clear view of the sky, the signal quality should always be fine. If placed too close, GPS receivers will be affected by interference from electronic devices.
Some cars have tinted windows with metallic content inside them that blocks GPS signals, basically anywhere near a high metallic density surface may interfere or completely block the GPS signals. Keeping a GPS tracker away from metallic objects and electronic equipment that are transmitting or receiving signals is important to prevent any interference.
A GPS tracker may also not work too close to a computer because the RF interference from it could prove to be too strong for the device to pick up signals.
These are all in the “may” category because with the improvements made in the field Of GPS, the signal quality is getting better by the day. Newer and advanced GPS trackers with high-tech chips will be better at picking up signals.