Brakes intermittently drags or sticks. Pads, calipers and rear rotors were replaced but brakes still sticking. What else shoyld be checked

Vehicle will need to be hoisted - brakes firmly applied with engine on - then release brakes and immediately check for any of the wheels that’s difficult to rotate .. Testing takes two people that are familiar with brake system troubleshooting.. Test may be repeated as necessary.. This should indicate where the problem lies so subsequent testing on the problem wheel can commence. Otherwise it is a guessing game!