Recently at Stansted I had an encounter with a security staff member who was of the opinion that both clotted cream and butter were liquids. (Note, I wasn't the one trying to get either of these onto the plane.) Her entire argument seemed to rest on the case that they were spreadable. I don't think she did well in GCSE physics.
For all the fuss about whether oat milk should be called milk, there are people of room temperature IQ level intelligence that get confused by peanut butter.