odd. usually a clicking sound is more related to the rear camera, as opposed to the front/selfie cam.
but putting that aside, check and make sure your front camera flex cable is seated correctly and solidly in its socket. also check to see if there's any damage to the flex cable. a lot of times, when something isn't working correctly after a reassembly, it's a good idea to revisit thing, put the back together again, reseat things, etc.