My wife traveled with my kids and all of their boarding passes show TSA Pre on them (we all have individual Global Entry accounts). But the agent stopped by wife, claiming the system doesn't show her as having it. Told her to go back to airline counter to "fix it". Wife did that, and airline counter said the boarding pass shows TSA Pre and that's all the prove there should be. Return to Pre line. While in line waiting wife saw many pax turned away with same reason, all without a fight. Finally my wife decided to stood her ground and told him it's illogical so many have been turned away, it must be their system. The agent reluctantly key in her KTN (she has her Global Entry Card) and it shows she is indeed in Pre and there's something wrong with the system on boarding pass scans that shows false negatives.

All that is to say, TSA Pre is exactly how every American used to go through airport security (much faster with polite helpful privately hired agents). Now our tax money is used to pay $70,000 a year salary TSA agent that do nothing but yell at you and repeatedly failed their own internal security audit so much that they will now not publish internal audit results.