I've been in contact with Samsung support via Twitter today so they are at least aware of the issues now, as are the developers apparently. Point taken about the fact it's not only Samsung, but we are hopefully a small step closer to a possible resolution.
Funnily enough i had a new bluetooth speaker delivered today and that seems to worth fine, unlike my car that disconnects all the time.
That says to me that it's specific use cases that fail, not bluetooth in its entirety, presumably why it wasn't seen in testing.
I'm currently using an old iPhone 4 on the car via bluetooth and that's fine, so nothing wrong with the car (and i used my phone before the Pie update for months without issues as well).
Hopefully we may get an update soon...
I've been doing a bit more investigation this morning, and there is definitely a wierd interaction between the phone and the car (Jaguar XE 67 plate) that's causing the issue.
I started by deleting all the pairing information on the Car and on the Phone (Samsung Galaxy S8+ running Pie).
I then connected the two devices via bluetooth, leaving the car system sat at the Bluetooth screen (see the image, take note of the Bluetooth tick box at the top of the menu in the image below) and the Phone sat at the paired devices screen.
Without playing anything or doing anything else on the phone, what I then observed was that the phone and the car went through a cycle of reconnect and disconnect with each other.
The car kept unticking the box and presumably rebooting its bluetooth connection, and the phones bluetooth connection for the car kept disconnecting and reconnecting. At times the phone seemed to indicate it was still connected although the car bluetooth system was clearly in a reboot mode, as it was unticked and the whole onscreen menu was greyed out.
I then went into the paired devices submenu on the phone against the car's connection and unchecked the "Use for Calls" and that made the connection more stable. Nothing seemed to disconnect on either side for a few minutes.
I then started playing some music via Spotify on the phone and left it for a few minutes, without any disconnects or reconnects, or skips in the music.
At this point I thought it was fixed (not being able to make or receive phone calls aside).
I then navigated back to the main menu on the car, clicked on the Media tab and the whole infotainment system on the car went black and none of the menus, even pressed to access via the hard keys, would show on the screen.
Powering the car on and off again via the start button didn't help - the dashboard controls lit up, heater came on etc. but the info screen was dead. This is what happened yesterday and I had to leave the car powered off for 10 minutes before the in-car system would even start again.
Hopefully this is of use to the Samsung developers. I will send a log via the Samsung Members app as well now.
Yes, it is very frustrating.
I've been conversing with Samsung UK via Twitter over the weekend and they assure me that the developers are aware and hopefully working on a fix.
I must say however that I'm in the same camp as some others on this thread. As it's a legal requirement in the UK to only use a phone hands-free in the car, something that really should be a commodity for phones these days, if it's not fixed in a timely fashion I'll have no choice but to move away from android back to apple.