What I wouldn't do is listen to thenooblord, the white plastic spacer is there to keep the main nozzle assembly strait and from bending. I would, remove the main nozzle assembly, then gently but firmly, move the white spacer up a bit then, using rubbing alcohol or dish soap which ever you prefer, clean the seating area of the white spacer. Then when dry, apply superglue to the walls of where it will be seated and then around the edges near the back of the bolt carrier. I would then let it air for 24 hrs to be compelty dry, then replace the entire nozzle assembly (the black tube is part of this) tighten and you will be good to go.
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