why does my moto g5s plus switch back and forth from 4g to 2g to no service?

[lessnless]

I bought an unlocked moto g5s plus at Best Buy (last year?). I'm using it in India but having problems with mobile data. I have airtel 4g data package but it frequently has no service, switches from 4g to 2g, back to no service on either, etc. I have reset to default, switched off/on mobile data & airplane mode, restarted phone, etc., which sometimes works but not always. I have tried the same airtel chip in a moto e5 phone and it always is 4g. I tried a new chip with the same results, and another chip for a different airtel number that always has 4g in a samsung galaxy S5, with the same results. An earlier thread didn't seem to solve the problem. Any suggestions? Thanks.

 

[B. Diddy]

Welcome to Android Central! What's the exact model number of the G5S Plus (in Settings>About Phone​)?