If you're unsure which Fitbit account you're using, you can verify the account you're connected to by going to the Fitbit app, tapping on the gear icon at the top right, scrolling down and tapping "Account Settings," and then "Change Email Address". Note the email address you're logged in with.
Then disconnect "Fitbit" in the Mia Health app, and when you reconnect, make sure to connect with the same email address you found in the Fitbit app.
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