C7 Squealing brakes?

my 2015 C77 (Z51- 12,000 miles) has a chronic issue with a "squealing" right rear wheel brake. Occurs when braking at a low speed approaching a stop; dry weather wet weather,whatever. Rotor and pads look fine to me so I took it to the Dealer who looked at it and said nothing wrong and then showed me a service bulletin that says one way to resolve squeal is to brake harder! Tried this but no relief. Besides, I don't think stomping on the brake is a technically acceptable solution for a sophisticated braking system on a sophisticated, high quality product like the Corvette! Anyone had this or have any thoughts on what I should instruct the Dealer to consider? Thanks!