Simple verification:
If you have installed and configured the device per manufacturer's instructions - a quick test to verify the connection is to simply walk outside with your device and it's paired external receiver in operation as expected.
Set the GNSS receiver down and walk away with your paired phone or tablet still in your hand.
-If the GPS icon on the map/app follows your position as you walk - it is still using the device's internal GPS chip.
-If the GPS icon on the map/app stays at the point where you set down the external GNSS receiver as you walk away; it's connected to the (stationary) external receiver.
(Conversely - you can have a colleague walk away from you holding just the GNSS receiver - if the GPS icon moves along with them as you remain standing still - this also verifies the connection is working.)
[Exact specifications as to the accuracy of your GNSS Receiver and its current configuration are another story...
but this will show you if have a working connection.]
