The information in this article will help you if a deleted character or island from Animal Crossing: New Horizons is still appearing in NookLink on the Nintendo Switch Online app.
Complete these steps
Once you have created a new character or island that you want to associate with NookLink, activate NookLink from the Animal Crossing: New Horizons title screen.
Launch the game from the Nintendo Switch HOME Menu.
On the title screen, press the (-) Button (Settings).
Select NookLink settings, then Yes, please.
Launch the Nintendo Switch Online app on your smart device and link the same Nintendo Account that you use with Animal Crossing: New Horizons.
Select Animal Crossing: New Horizons to access NookLink.
If the previous character is still displaying, select Settings, then Change players to manually select your current character.