Mine are like that. They can use the catflap but if the staff are around they sit there looking helpless.
Our cat Freddie has never come when called, in fact if he sees us when out he runs off if he doesn't want to come in pretending he hasn't seen us.
OUr new cat, Lily, rarely comes when called. When she wants to come in she sits on the outside of the living-room window and taps on it if we don't notice.