I’m experiencing this too at my car radio (build in year 2013). For some reason the connection gets lost more often or fewer sometimes. I can’t reproduce the error exactly.
Workaround for me to get less connection losses is to go to the developer options and set “Bluetooth AVRCP-Version” from “AVRCP 1.6” to “AVRCP 1.3”. It can be necessary to reboot your phone after that. With this older version you will loose some features on modern devices like showing cover art of the playing title but for me it’s okay.