Thanks ShannonM1 for the effort. So problem partially resolved for cable only.
It appears that the very first time you connect the phone to use as a CC webcam, the 'drivers' may not register/update/resolve correctly. So although everything functioned except the microphone (strange the phone camera listed and with video feed but not the microphone from the same device).
Once I had powered down and rebooted the computer, cable connection only works correctly.......wifi not so.
Wifi connection does not function and the device connectivity on both video/microphone is lost when disconnecting the lightning cable. Furthermore, the "desk view camera" from phone is listed ok, but the webcam/front camera which was listed on cable connection (when both listed as available) disappears as does microphone.
At least it is usable - but the wifi connection claims is possible too - is not happening! Bluetooth is active. Multiple attempts connecting with and without cable and checking 'sound' system settings etc.
It would be useful to know if the phone is relying on a wifi connection to the network router for CC webcam, or directly to the computer. Either way, wifi CCwebcam no beuno!
Further troubleshooting findngs: when on wifi and I unlock/relock the phone, the camera and microphone list correctly and are showing for selection - the CCw connection page shows connected on the phone too. A small step forward, although now they are displaying as connected, neither video or mic (no input level displaying) stream are happening - again this bug only on wifi connection.