Chinese proverb: Go the mountain and meet the tiger.
In other words, It is a probably a difficult path to fix it.
Such cases dealing with hardware related issues need specific experience, which only few users may have. So we may not find a direct answer.
Generic path
Look for "debug" & "troubleshooting" instruction
wiki.ubuntu.com - DebuggingBluetooth
May check other distribution with same stack
wiki.archlinux.org - Bluetooth #Troubleshooting
An interesting tool hcidump
to get verbose logs, check for use cases here in AU or Unix.SE.
Note: Documentation changes slower than tools themselves, so watch for last update date on web-pages and trust local man
-pages.
Most debug instructions at some point, ask to test the edge development code or binary build.
If the Bluetooth device is a USB one (like major laptops), then it is possible to try any testing setup without touching your current production system using VirtualBox with the extension pack.
Ask Ubuntu a question or Submit a Bug Report (Ubuntu/LP or may be Upstream project). This is up to your evaluation where previously collected data are leading to.
blueman-applet
, currently I have the version 2.0.5 which behaves quite well.