It just works like a charm in Linux Mint 19.3. I've tried 4 different pairs of BT 4.0 and 5.0 headsets and headphones, all work right away in Linux Mint 19.3. No problem at all. Also, I've tried one BT mouse I have, and it still works without any problem. Every BT devices I've tried, all work smoothly. There are around 10 other BT devices and 4 cellular phones working within 15 meters around my test environment. And, I don't feel any interference during my test(playing music continuously while moving mouse around my screen desktop).