the Mac Mini away from any #WiFi sources to avoid signal contamination. The desk has been rearranged to move the #Netgear #Orbi Mesh router as far away as possible from the Mini.

3) Do a full reset of the Bluetooth configurationon the Mac and re-pair all devices - Not tried yet.

4) Switch to using a third party Bluetooth adaptor - in particular this #Hideez device and switch to using that instead of the default Bluetooth stack. I've placed a query with them as to whether it works with (2/3)