Technical Support wrote:
Are you trying to shoot in live view mode? Canon Rebels cannot trigger "dumb" triggers (i.e. non-TTL) when in live view. Other Canons can, but must have a certain setting made.
The other possibility is the foot in the CC is not working correctly. Trying on a different camera will help determine the root cause.
You are correct. It will work if I turn off live view and use the optical viewfinder. This is very frustrating as I bought the camera specifically for the live view feature as I am shooting highly detailed engagement rings and can't see through the view finder if the shot is correct. Do you know if it would work if I connected the Cyber Commander through the HDMI port? Or can you think of any other work around?