Wifi on but ‘not connected to internet’

I also have an issue with internet connectivity in my 2023 Tahoe. I purchased a 5GB data plan when the previous one expired and since then Google services are not recognizing it. I keep getting a message that I need to purchase a data plan for some services to work fully. I am not able to download offline maps for the speed limit to work correctly again because Google Maps is not recognizing the active data plan. 

I called On-Star through the blue button and they were not able to resolve the issue. Now GM called me and are asking me to take the car to my local dealer who is asking to book/reserve a slot when available to look into the issue.

This is extremely frustrating as this is my only car and is specifically purchased for the purpose of transporting a  child with special needs.