Remote commands over Wi-Fi when no cell coverage

Hey,

I have a 2024 Hummer EV 3x SUV with active OnStar premium services (confirmed both in MyGMC app and on website) and car was able to receive and report back status and execute remote commands (lock/unlock, etc). Since December 16, 2024, car is not reporting status and cannot execute remote commands. 

Location of car was moved around this time to a zone with no cell coverage. However, garage has wi-fi and car is successfully connected. Checking in-car infotaiment system, the car reports "active" services, MyGMC Studio is connected and reports all items correctly, navigation works. 

However, I cannot execute remote commands to the car over wi-fi, which should not be by design. There are a lot of places, especially underground garage lots, where cell reception is poor. In these cases I would assume that in case wi-fi is available, the car should be able to report back SoC, receive and execute commands, etc. 

To check connectivity to OnStar, I tried calling from the OnStor button, but nothing happens. The car does not call OnStar services. Assuming this can ONLY be done over cell and not over wi-fi, this would explain the call not going through. But does that mean that the car DOES NOT report and execute commands over wi-fi? I.e. when there is no cell coverage, but good wi-fi to which the car is connected to, the OnStar services to which I am subscribed will not work?

Has anybody been able to access car status from MyGMC, etc apps and execute remote commands over wi-fi?

Thanks!