Yes, this has been an oversight issue since the Fame pack was released. Fame affects family members the exact same way it affects strangers, and makes it impossible to properly interact even in the same household. I turned Fame off a long time ago because this makes it unusable in my game. I like to play with multi-Sim households but if one or more of them starts to generate fame, eventually this cuts them off socially from their household unless I exclusively interact using the famous Sim.
This needs to be changed so that fame does not affect family or even current relationships.