Sounds like a bug - youd have to test something like 4.14 where i know this worked fine to confirm if this is your setup or not.
Should it not work in such a dated version either, then your setup is missing something basic - like setting a value somehwere for either sleep or strength needed to break, or something more basic is going on…
For instance, the player capsule is colliding with the item, thus causing the constraint to fail (often the case with weapons, as you usually want them to collide to other players).