My R7 has developed a quirk and I can't find how to fix it. When I switch it on, there is a delay of about 10 seconds before it will come to life and allow me to take pictures. At first I thought it was a dirty camera/lens connection but it also happens when I go to image playback and the lens isn't even connected. So now I'm thinking I've accidentally changed a setting and I can't find where. Does anyone have any ideas?