Thanks for the report, simps. And very glad to hear it all came around for you and is now working. I'll admit, I feel like I had to loop that "activation" step a couple of times as well, before it started acting like it was activated for me. There is something amiss in there... But all is well that ends well. If everything works, DON'T UPDATE!
@2018 Denali -- I fear you may be correct. Which is a total bummer! Why us? The CPlay2Air website clearly states that ALL GMC 2016-2019 vehicles are supported if, "*Vehicles must come equipped with factory CarPlay". Which ours do. We know it's a firmware issue because it used to work fine, in previous firmwares. They've broken something and now they need to fix it! There is no excuse for not releasing a new firmware to resolve our issue, or remove the downgrade/rollback block. They can't leave us in limbo, with broken $150 adapters, that are advertised to work in our vehicles.
Is it just Denali and me? Anyone else have the 5-minute audio issue as well? Sorry if I'm beating a dead horse here, but I am curious if this is exclusively a GM issue. Are there any other vehicle makes out there that are suffering this? Please sound off if you are in the same boat!