If you have sent funds to your Nook wallet, but they haven't arrived, your Bank might be preventing the transfer. Some banks restrict making first payments to a new beneficiary through Open Banking, and some banks also impose limits on the amount you can send to a new recipient such as Nook.
Check out this useful article which outlines some limits set by some of the main banks our customers use.
If there is a delay in the payment reaching the account and it is not due to a reason you are aware of, you should contact them to find out why and to answer any questions they have. We are always happy to support with any information they need.