That’s intended behavior, we made some changes to the way you can subscribe to decks. You don’t have to copy the deck id anymore, you just need to subscribe on the AnkiHub website. See Subscribe to a Deck - AnkiHub for more information.
If you want to use the deck the add-on asks you about, then click on the Install button.
If you don’t want to use it, unsubscribe from the deck on the AnkiHub website.
Hope this helps!