I tried everything you mentioned and more. Nothing worked until I finally found a crazy weird solution:
First I duplicated my entire comp and deleted everything except for that second clip with the incorrect frame. Even isolated within this new comp, the clip still was still stuck with that single frame showing the girl. The frames before and after were correct. Then I dropped a black solid beneath the clip and BOOM! The frame was now correct. So I dropped this new comp back into my original… and the frame was still wrong! It wasn’t until I deleted the original bad clip below it that the frame finally displayed correctly in my original comp.
I can’t explain how or why any of this happened. It seems like something was being cached incorrectly, but I cleaned out my cache multiple times when trying various solutions and it never helped.