[General Questions and Answers] Cannon_Foddr:
Phone Motorola One Vision (unlocked but NOT rooted)

Recently got updated (in UK) to Android 11 ~ 24th August 2021

Received a Security Update (dated 1 August) on 1st September 2021

Problem: Bluetooth will not stay connected - phone 'sees' whatever I try to connect to, it might 'connect' but then disconnects - depending on device it may take a few attempts before giving up

Firstly before anyone says 'search for it' - I have.

I've seen many posts about Android 11 & it's 'broken' bluetooth & the many so-called temporary fixes - but nothing works for me

(Clear Cache/Data, Reset Networks, Delete/Upair & reconnect etc) - Only thing I've not done is a full Phone factory reset

When the phone got updated to Android 11 everything went smoothly, except I had to go through all my Apps & (re)give the necessary permission to SD card etc. This also meant my Car Infosystem (SYNC 3 on a 2018 Ford C-max) didn't recognise my phone - so I deleted it & reconnected it & afaik for the week I was on Android 11 the phone stayed connected without any problems.

My Bluetooth Earbuds (cheap pair off of Amazon) still worked without any sound drop-off & My Amazefit Bip watch also stayed connected (apart from the occasional 'hiccup' when the App I use gets an update)

I then received a 'Security Update' a week later & now I've noticed Bluetooth is NFG (No F-ing Good).

When I try to pair up, the device(s) are seen (whether the car, earbuds or another phone) - I get the usual 'Check Pin matches the same as...' messages & I confirm.... then the phone disconnects/reconnects/disconnects until it finally gives up

In the case of the Car connection I get additional messages such as 'Allow Access to messages - An Untrusted Bluetooth device Ford C-Max, wants to access your messages' & I also get 'Bluetooth has stopped' pop-ups

In the case of Pairing up Phones - it just connects & disconnects, sometime when trying to reconnect - it doesn't even try to connect

The ONLY things that seems to stay connected is my Amazefit Bip watch - & ironically this is the only thing that DOESN'T show up as a 'Previously connected device' under Bluetooth

To try & figure this out I've tried all the usual tricks mentioned on Google Searches (as mentioned above), as well as trying different AVRCP & MAP options under the Phones 'Developer options' (even the 'Enable Gabeldorsche' option that apprently is suppose to stabilise connections)

- Nothing I've tried lets me stay connected more than a few seconds.

As I mentioned earlier I googled a lot & I see that Android 11 has had Bluetooth connection problems for a long time (posts I've seen go back to Feb 2012) & it's not just on one particular phone manufacturer - all the solutions given are basically all the same thing repeated, which I've tried (apart from the full manufacturer reset)

But as mentioned - these are 'old posts' (a few months old) & my questions are.....

Is there a permanent 'fix' for Android 11 Bluetooth connection problem ?

Do I/Will I have to wait until a proper fix is sent ? (afaik all this has happened due to the last 'Security Update' I received)

Is there a way to 'roll-back' to the previous Security Update (remember my Phone isn't rooted) - just to prove it's the update that caused the problem ?

or am I totally 'up-the-creek-without-a-paddle' do to a muck up by Google/Android developers ?