I am running Carbon rom (have tried several different roms with the same results) and when I pair it with my Uconnect 8.4a system on my Ram 1500 it goes through the usual process of pairing, downloading the phones contact list and then it starts asking my permission to access my call logs and contact list. Then it will ask me to access my messages, if I answer yes to all of these then bluetooth starts an endless cycle of crashing and restarting and the only way I can stop it is to disable bluetooth on the phone.
Ok, that was the issue and here is what has worked for me to fix it.
1. In bluetooth settings on the phone set bluetooth to always be visible. May or may not be necessary on yours but it was on mine.
2. when pairing to the infotainment system do not allow it to access your messages. The Uconnect system reads out your text messages as they arrive and for some reason it doesn't work well with AOSP based roms. I hate this feature anyway so it's no sweat to me not having it. It's annoying for me to have whatever I'm listening to interrupted by a stupid text message! It can wait people!
Hope this helps someone!