The drivers appear to be up to date too. There are 2 cameras I have one doesn't work with icam at all (a gearhead cam) and the other is the one I was referring to in my original post (Logitech C15).
I did discover something interesting last night while trying to test solutions. I had turned off the light and then realised that it didn't do the "connection closed" crash over cellular data it always does. I was able to hear the audio and as soon as I turned on the light it IMMEDIATELY crashed again. With the light off it was pitch black but I did see the dim led indicator light on my partner's computer, so there was video being transmitted. I tested this 3 more times with the same result. If the light was off, audio and video came through, but it crashed as soon as the light was turned on. giving me the same "connection closed"