This issue is rare. Sometimes the nylon ring inside the tube slips out of place, and the adjustment collar cannot tighten fully. You can fix it in a minute.


Look inside the collar. You will see a white plastic spacer.
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Push the spacer so its front edge sits flush with the front lip of the collar. Make sure it is even all around.
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Put the collar back on the tube and screw it on clockwise until snug.

Tip: Collar needs to be somewhat loose for smaller pipe to slide out first.

If the collar still does not tighten or white plastic spacer is missing, contact support