John, Zafer,
I don't think that doing the 'Web Upgrade' will work in this case as it only updates (or in some cases, downdates) the 'core' BB1 Brennan code. If you are running on BB1 code 'BB1 Apr 22 2020' and you run the 'Web Upgrade' you will find that the version date will have changed to something like 'BB1 Mar 18 2020' BUT the Bluetooth will stack not have been changed (downdated).
The Bluetooth code is an independent and separate stack and, as far as I can see, will need a different course of action. One option would be to rebuild the SD card per the Brennan website instructions which would take your version back to October 2019, and then run the 'Web Upgrade' to get back to March 2020.
I hope that this will save some pain. If you go through the Web Upgrade only, and believe that the Bluetooth upgrade has been reversed then you will be heading down the rocky road of still having the original problem but looking at other (incorrect) causes.
The reason that the Bluetooth upgrade is done using the 'USB Upgrade' option underlines the above information.
Regards,
Peter.