The TCP Connection to Samsung-G988B has stopped working

The message I get is:

The TCP Connection to Samsung-G988B (my PC ip address) stopped working.

It seems to connect OK, then as soon as I play audio on my phone, it disconnects and this error message appears.

Please can you advise of a fix?

If you mean that you play audio from another Android application, please do this:
On your phone, go to AudioRelay’s settings and deactivate exclusive audio.