Google map showing incorrect location and OnStar not connected

I have Chevy equinox ev lt2 2025 on lease since April 2025  

After first few months,  Then the GPS started showing that I was in places that were 100 miles away.  That is when I pressed my OnStar button, which did not work.  So I called OnStar.  They told me that since the OnStar button was still green, to take the car to my dealership & tell them OnStar said it was the telematics module.  I brought it to the dealership. They sent me right home because they said it would take some time to even diagnose the issue and the diagnosis will determine how long a repair will be. 

After that we had multiple calls with OnStar and dealer but no help so far. We had appointment today 12th November 2025 with Andean Chevrolet Cumming GA, technician didn’t see the issue at all and tried to sell on star membership.  it is clear that with  on star basic free membership Google Maps should work and it is working for many of my friend.  They are saying we need to buy paid membership.  now I have appointment again on November 17th.  Hope this time it should be resolved.  
One guy indicated antenna issue  

no one suggested rot cause and solution so far.