Could be related to the game doing weird device polling every now and then.
Not the first time I’ve seen it happen. I once had a keyboard that caused some games to basically run at 1 FPS while it was connected for no apparent reason beyond those games polling the keyboard or its keys in a certain way that triggered a really obscure bug.
People use the term as a catch-all for all sorts of things.
Remember back when it was mostly only used to refer to the whack frame pacing of SLI setups that caused microstuttering even in situations where the player otherwise had a perfect 60 FPS?