I've just bought a NIB pro, sometimes it happens to me too. What I am wondering is that my loop looks different to the ones in the pictures. mine has metal on top, not mylar. this probably is an attempt to avoid the issue, but it still happens.
Did Stern change the design or I am missing something?
EdiT: found this https://www.instagram.com/p/B87ihk8BRNd/?igshid=v8cvna5k4dfi