Welcome. It would help if you told us where you're located if you want some local recommendations. You don't necessarily need to take your rig to an RV repair shop. It doesn't sound like the problem is related to your rig being an RV. Most large truck repair shops and a lot of others can diagnose and repair the problem you describe. If you broaden your search, you'll have more options.
2021 Holiday Rambler Armada 44LE
2021 Jeep Wrangler High Altitude toad w/Ready Brute Elite II