Threats are common. I was flying within the USA with a young toddler still nursing. We had some breast milk and was ordered to dump it, by a TSA agent, standing in front of a sign saying milk was fine.

I mentioned the sign and was threatened with a "deep" inspection and guaranteed enough detention time to miss the flight.

We dumped it, boarded a 5 hour flight, pushed the call button and asked for cow milk to help get through the flight. They came back, 3 other moms did the exact same thing, and got told they were out of milk.

Quite unpleasant, security theater is such a waste.