Bluetooth & Linux, pain in the butt

Just for info - this is the configuration that is working for me (after disabling the internal bluetooth adapter as described in the link I posted above):

• x86_64 computer bought 2013
  
• up-to-date Debian Bullseye with kernel 5.10
  
• Chromium (I wouldn't use Chrome either)
  
• a cheap bluetooth adapter that is working out of the box with the Debian main repositories.