15+ Years Ago, I used ones that locked and ones that just "snapped" into place as extra security protection and b/c one of my folding bags tended to open wide during transit. It was also a handy way to identify my bag in a sea of black bags. Check in agents (Virgini and BA in UK), Delta in the USA, Singapore in Asia and SAA in South Africa would often tell me I have to remove it b/c it could get caught in the bagged machinery. After I lost or lost track of them, I stopped using them (and the wonky folding bag).

Maybe it got caught and broke or a "helpful" handler just cut it and removed it to prevent it from (or when it did) jam some piece of equipment.