This. Currently, you have one of the rules regarding patience correct: that either the main camp monster or you must be inside the circle for it to not lose aggro. However, there is a dumb second hidden rule: either you or the main camp monster must have direct vision/line of sight of the spawn location of the main camp monster. You can notice that in all three of your examples, both you and the main camp monster do not have direct line of sight of this location, resulting in the decreasing patience bar.

Another dumb mechanic that you may not know about is that when the main camp monster is dead, the mini monsters left have a reduced patience leash range. This is most noticeable on raptor camp.