As stated at https://community.flexradio.com/discussion/7982392/xsdr6000-mac-solution-to-ssdr/p2 the TX part is still not implemented when choosing PC mic input (i.e. transmitting audio from your macOS).
It is working with locally radio-attached microphone. ATU and TX switching is working, but not the TX audio sound.
I put the issue here to keep a remainder to whom may be searching elsewhere for a solution.
As stated at https://community.flexradio.com/discussion/7982392/xsdr6000-mac-solution-to-ssdr/p2 the TX part is still not implemented when choosing PC mic input (i.e. transmitting audio from your macOS). It is working with locally radio-attached microphone. ATU and TX switching is working, but not the TX audio sound. I put the issue here to keep a remainder to whom may be searching elsewhere for a solution.