This can happen most commonly if a friend has logged into your Deck Tracker or if you had a previous account that you no longer use. In order to fix this, we need to get the right account
Ensure that you're logged in on the website (HSReplay.net) with the correct account.
Logout of HDT (Options > HSReplay.net > Log Out/Disconnect)
Log back in to HDT
If these don't fix the issue, submit a ticket, and we'll look into your account.