GPS and Network

We can get the location after selecting the network from the location provider after the application is turned on, but why can not we get it when GPS is selected?

what do you mean by that, can you elaborate your question ?

We can get service provider network position, but we can not get the position when we make GPS

My phone is LG G5. Could it be the problem ?

Are you testing it outdoors? Remember that GPS only works outdoors, and it can take up to 10 minutes to get a first fix.