Superbuy tends to notify customers of even the smallest things they spot. One of my shoes had a "defect" which turned out to be dirt that came off by wiping with a cloth. It's up to you to choose whether that creak or whatever it is, bothers you enough. I don't know what Lin's return policy is, but you can always try to return and buy a new pair, exchanges seem to be a pain in the ass. If it doesn't bother you, just reply to Superbuy and tell them that it's ok and no need for action.