the setting is only to turn off the build in bluetooth in RPi3.
I am sorry that you have problems with bluetooth. Trying to follow your problem description, one typical cause of errors is usually the power supply of the Pi. Different setups need different amounts of „power“ and when powering the Pi just via GPIO pins and running the Squeezebox Server and stream via bluetooth to Squeezelite instances the Pi might suffer from power lacks. It is not only an advertisement you are referencing – indeed we are testing all devices and setups that we send to our customers. The modularity of the plugin based project and the freedom to use Max2Play just makes it impossible to test every scenario. This is why we try to help the best we can in this forum 🙂
All the Best