Progress reset error diablo 3

My progress was reset because of the new season… I started from the beginning and made a lot of progress but when I closed and opened my diablo game all my progress was reset again. I am playing on Nintendo switch. I still kept my level and gear but all of my achievements were back to not completed yet.

How do I fix this?

Thanks

Anytime you start a new season, your progress is “reset” so to speak for seasonal players. Are you making sure you are logging in as season vs non season?