I have upgraded my iPhone today after doing a backup and I lost all my data. Could not remember my password, reset it and when I was finally able to enter the application, I was back to square one. Very very discouraged!
Are you using the correct email address to log in with? Did you perhaps have two accounts with different email addresses setup, and you’re logged in with the wrong one?
The App stores your data on the web site so all you need to do with a new phone is to download the app and then login with your original username and password.
The login function can be difficult to find and may be different depending on which app you use (iOS or Android).
You seem to have at least two accounts, which are subscribed to Duolingo Plus.
This might be your other account
Your data and progress are better to see in your personal (unofficial, but very useful) webpages in:
You might ask Duolingo's staff for further help via "email support for Plus users" in your account.