Hi
Make sure not standing still while going upstairs, as that can interrupt the count. Carrying something heavy could also make the tracker unable to count floors.
Feel free to check out the Fitbit Article:
How does my Fitbit device count floors?
Best AnswerFastest to exchange at store of purchase (with receipt) or feel free to contact the fitbit support team:
http://contact.fitbit.com
Mention what you've already tried to speed things up.
Best Answer