Welcome to the forum.
First, we will need more information to be of much help. This ARTICLE will give you tips on the types of info, that would be so very useful.
Then, could you tell use where the scene, that repeats itself, in two directions, is coming from? It might be good to post a screen-cap of the Timeline, with pointers to the Clip, or portion of a Clip, that is appearing where it should not be.
Last, can you look at this ARTICLE, and see if anything applies to your Timeline? An orphan, or two, or three, would be my first guess.