I installed a front camera in my 2012 Toyota camry. I have the max10 unit. The front camera works and the backup camera works. When I activate F-CAM it brings up the font camera. When i try to switch between the front and back cameras, I get the yellow exclamation sign for the back camera. When I put in reverse, the back camera works, then switches to front camera when i put the car in drive. Why can't I switch between front and back cameras when using the F-Cam feature?