you moved cards from an AnkiHub deck that you were subscribed to (not as a maintainer) into a different deck (of which you are the maintainer)
you are trying to add those cards to your deck
AnkiHub allows you to move notes into a different deck after subscribing. Those notes will continue to “belong,” to the original AnkiHub deck, even if you move them. So it is trying to submit those suggestions to the deck they originally belonged to. If you want to do this, I believe you will need to create copies of those notes first and then submit suggestions. At that point, they will get new Anki/AnkiHub IDs.
However, keep in mind that if you do this, your subscribers may end up with duplicate notes if they are also subscribed to the deck from which you copied these notes from.