Guide pins stuck, or pads hung up in mounts where they slide back and forth. Should slide easy. Also on rear, after winding piston out you cycle e brake lever to walk piston out until pads contact rotor.
And make sure pins on back of pads seat in notches on piston.
To keep rear brakes adjusted, the e-brake needs to be cycled.
If not due to cable sticking,then manually activate at every oil change.