I use two or three different blue tooth audio with mine, small guitar amp with blue tooth support, blue tooth receiver with jack out to X1000 audio in, and actual bluetooth headphones.
I find two issues when connecting them
1. Often my phone gets there first, preventing proper connection, even if "paired" so make sure any other devices that you have used them with are not stealing the connection, can be fiddly with devices without GUI of some kind.
2. Occasionally connection needs cycling on and off a couple of times. Less often I need to start from a fresh session on the A600GS.
The final ting to check is that the attached and working device is selected in the audio setting section, this *should* happen automatically for new connections, but might need manually setting if settings have been edited by you at some point.