Hi mathew1969, welcome to the community.
The support rep was correct, if you use the local recording option and record directly to your computer only the shared screen and audio conference are captured. If you want to capture the shared webcams as well you need to select the Cloud recording options instead. Get Started with Recording
The webcam stream is separate from the shared screen, it has a much higher refresh rate and uses more data. In our testing, including the webcam stream in the local recording while you are Presenting and sharing your screen typically resulted in performance issues which affected the webinar because it was too much for the average computer.
