One more thing to check is your timing on the praising. Are you actually praising them when their activity message says "Working on Career" or praising them AFTER their focus changes to whatever other activity is going to happen? Remember their focus can change while they're at the end of one activity before they're actually walking to the new activity. That seems to be a big possibility since all 5 of the families are doing it.

If this is inadvertently happening, they are being rewarded for leaving work, so yes, they will keep it up because they've been trained to do so.

Maybe? Seems like it's the only explanation... (dunno )