SEA Nov 30, around 11am.

Me, wife, and 5 year old all got 3 beeps. Lap infant got 1 beep.

TSA contractor said no Pre-Check for us. I said the 1 beep was for infant. He asked, "Who is infant?" (As in, "infant" was someone's first name). I said the baby is a lap infant. He again said no Pre-Check.

I turned to the TSA agent who was manning the Priority/Premium lane, and she initially said to use the Pre-Check lane, then after being shouted at by the TSA contractor, she told me to enter the Priority/Premium lane, saying that it was Pre-Check.

Luckily, we found another TSA agent who understood the stupidity that just happened. He opened up the ropes and led us into the Pre-Check lane. The TSA agent at the BP check (just prior to x-ray) had no issue.