Seems that moonbutterflies require smaller distance to be fed than other inventory critters, like rabbits, bees or regular butterflies. This causes the character to run into Chester, Hutch or Woby endlessly. Notice how, when feeding inside a chest, the character moves closer to the chest to feed the moths.
Put moon moths into a container that has physical collision with a player - Chester, Hutch, or Woby. Try to feed the moths.