I had the same issue. What I did, I cleaned off all the break dust on the brake clips and added CRC SILARAMIC Brake System Grease on the back plates of the brake pads and regreased all the caliper components with CRC caliper grease and the noise never returned since. I believe it's all the brake dust building up and caking on to the components. Give it a good clean and you should be good to go.
Last edited by antiks; 12-06-2019 at 11:48 AM.