OnStar breaking up, they can't communicate with my car

[Bulging_Eye]

My OnStar has been crackling, breaking up and very slow to respond since November of 2021.  I've contacted them about three or four times and was first told that my car needed an update and they couldn't communicate with it.  I was told take it to a dealer and get it fixed.  Here we are two trips to the Chevrolet dealer later, both times chevrolet service department said "NOTHING IS WRONG WITH MY ONSTAR OR MY VEHICLE:  So I guess I will stop paying for it since I can't resolve this by myself.  I suspect it has to do with the 5G upgrade but nothing I can do about that.

[Advisor_Kaitlyn]

Dealerships are great for assistance when you are experiencing hardware concerns with your OnStar system. If the LED near your OnStar button is red, that is a key indicator that there is something wrong with your unit. The best initial step is to push you blue OnStar button to have a live Advisor perform an On Demand Diagnostics (ODD). From here, we can see if an additional trip to the dealership would be necessary.

Do you experience this concern only during a specific time such as speaking with a live Advisor? If you can provide our team with additional details in an email, we can look into your account on our end and see what further steps we can provide. You can reach us at socialmedia@gm.com and we ask that you have your subject line as ‘ATTN: OnStar Community/Bulging_Eye’ so we can reference back to this post.

[SK]

Just another "perk" of being a paying customer. No support, more work for you and the bill coming due to put the "cherry on top." I bought a brand new Yukon Denali and my unlimited PRE PAID plan was removed from the account. Nearly a month later, OnStar has been unable to add this plan back, so I am just waiting for the stop-gap trial to end and leave me without a functional navigation system in a >$85k vehicle. 

The issue isn't with your car, Bulging_Eye; it's the lack of support from OnStar! Hoping you don't need the service you are being charged for in the event of emergency.

[Bulging_Eye]

I've taken my vehicle to the dealer twice now.  Both times they have told me "there is nothing wrong with your OnStar system".  The second visit they actually called an OnStar tech and came to the same conclusion.  So, it still isn't working properly.