Try a test by moving the rendered clip further down and away from the lower tracks. You might be amazed! - After all, the cursor spans all the media that is apparent under it. So, within those tracks maybe all sorts of media - text; dissolves; fxs . . etc etc . . - just because you can't"see" them in the preview, it doesn't mean that they aren't there for an operation to be done to them - yeah? Another test you want to try out is to "Solo" your rendered track OR to mute those tracks you don't want to be "functioning" while you "preview" your rendered clip - yeah?

. . . hmmmm . .

Grazie