Hello friends, I ran into that issue myself quite a bit. Every now and then I have to reestablish network connections from LTE/CDMA over to automatic. If you haven't tried that I will post a walk through below. Or another way you can hit the network towers is to dial ##72786# and press call. Easy explanation is it just needs a little BOOST to reconnect to network towers! Hope that could be some help!
Settings-Connections-Mobile Networks- Network Mode- (toggle to automatically or to LTE/CDMA) Let me know if that helps.
P.s Hey Boost looking for another phone tech online support advocate I'm available!
My son is having this issue and getting the run around. He has tried the ##72786# and received a message that the number can not be reached. This phone has not worked from the start for a couple weeks now. Each time he calls Boost he gets the same story that the tower is out, while his father gets perfect service. Then he is told he will have his case escalated and a call back will be received that never arrives. This is theft of service and faulty goods. This is ridiculous.