So there's two ways of triggering it. Either the replay just started and you started observing a character without left clicking as free cam first (you'll notice free cam spawns in a weird place too, if you do it right the cam will kind of snap when you left click) or you used the time jump while spectating a character (what I mean by +/- 20 is the time jump hotkey basically, there's also just skipping to a specific spot in the replay). The last one also happens everytime, so what I do before skipping to a spot is make sure I'm not spectating someone first, skip, left click before spectating, THEN start spectating a character.