Wordlist Anyone know a place that can actually fix the auto start/stop on my Yukon?

[forumbacklinks2]

So my 2017 Yukon Denali has this annoying issue where the auto start/stop system just randomly decides not to work, and the message on the dash keeps saying "engine on due to vehicle charging" or something like that, even though I've had the battery checked twice and it's supposedly in good condition. I've read online that these trucks are really sensitive to battery health and sometimes even a slight voltage drop can cause the system to disable itself, but I've also heard it could be related to the auxiliary battery or some sensor that's gone bad, and honestly I have no idea where to even start with diagnosing this thing. I've taken it to a couple of general garages and they just shrugged and said it's probably normal behavior, but I know for a fact it used to work perfectly and now it hardly ever engages, which isn't a huge deal in terms of drivability but it's annoying knowing something isn't right. I'm thinking I need to find a professional GMC repair shop in Musaffah Abu Dhabi that actually has experience with these specific systems and knows how to properly diagnose the start/stop functionality rather than just telling me to ignore it. If anyone here has dealt with a similar issue on their Yukon or Tahoe and managed to get it resolved, I'd love to know what the actual problem was and how much it cost to fix, because I don't want to spend a fortune chasing a problem that might be something simple in the end.