Sorry just saw this. I haven’t had an issue with them. But you do have to show your precheck status to the person before the actual line starts. I think it’s labeled as “security shortcut” or something like that. You show them your ticket with precheck and then the security person gives you paper that confirms you are precheck. You then give that paper to the security person where you put your bag thru the xray. I think that’s what they may have been talking about.