Either the last working outlet, or the first non-working outlet, on that line has an intermittent connection problem. It is ONLY one of those two.
I was at my SIL's house yesterday. (My brother is deceased so I do her handyman work.) She was running a space heater and it lost power. She tried tripping and resetting the breaker, to no effect.
I traced it down to an outlet in another room. It was the "first non-working" outlet. It was 30 years old, and the plastic had broken letting the clip holding the hot wire release the wire. She was astounded that it was an outlet in another room.