Has anyone had any problems using a sun hood on the camera

I think a sun hood on the camera would unbalance the gimbal, even if it is a lightweigh hood. Not advisable, IMHO...

Also, could result in vignetting. Try a ND filter.

Yes, I just purchased one as part of my new P4P package.  I use an iPhone7plus, in which the volume control buttons don't line up with the hood.  If I try to make it fit, the volume control "down" button gets pushed in and stuck when securing the phone to the bracket on the controller.  Furthermore, if you have any kind of iPhone case plus the hood, the brackets for the iPhone isn't wide enough to compensate for the thickness of both the phone case and the hood.  Great idea having a hood, however since phone sizes, dimensions, and location of plug for camera to controller are all different, there is no "one size fits all" solution.  As for viewing through the hood itself, on a sunny day it doesn't seem to make very much of a difference.  In fact, if you phone adjusts itself to the lighting conditions, it darkens the screen, leaving you right back to square one not being able to see the screen.  I don't use my hood, it sits in the box every time I fly.

Whoops.  Sorry, I just read the question again.  I didn't realize you meant specifically on the camera itself.  Like Antonio76 says, it would unbalance the gimbal, and probably even blow off like a windsock if you're flying at 32 miles per hour.

I would recommend you to consider the ND filter, instead of sun hood on camera directly.