so to help people with the red chest that needs a clue and the chain click see more on this comment for spoilers
click the chain to look at it one, spam click it to hear if it laughs, then look away from the chain and click the chain again and if it moved positions its fake.
the red chests with clues can be a few different things, like going to the rulebook and having to scan a QR code that says if its a mimic or not, there's also spam clicking the hinge until it falls off revealing an arrow pointing to the correct answer.