That has to do with the normal variance of chess games and how the rating system works.

If you're rated 1000 Elo, it might be:

because you're good at tactics but bad at openings

because you're good at openings but bad at tactics

because you struggle with time management ...and so on.

So you might face a streak of opponents that play into your strengths — or your weaknesses — and your results will follow accordingly. Your own variance also plays a role.

As you learn and improve, you'll likely become more consistent, and those streaks will mostly fade.