There is a possibility that the additional content has not been installed correctly on your PS5 console.
I apologize for the inconvenience, but please try the following steps:
■ Please restart PS5.
■ Please log out from "PlayStation Network" and try logging in again.
■ Please try restoring the license once whether reported issue is solve or not.
● How to restore license on PS5 (This is the link to SONY)
https://www.playstation.com/country-selector/index.html
1: Go to [Settings] > [Users and Accounts] > [Other] > [Restore Licenses].
2: Select [Restore], and try to access the contents after finishing restoration.
■ When logging in with the purchased PSN account, "**Game Name**" will be displayed in the game library. If you select 【○○】>【Download】, the screen to select the content to be installed will be displayed, and 【△△】is displayed, click【OK】to download.
■ If you have multiple PSN accounts, check other accounts as well.
■ Which destination is the game installed to:”PS5 internal SSD storage” or “M.2SSD storage in the expansion slot.
*If you are using the M.2SSD storage in the expansion slot, please try using the SSD storage in the main unit, and please try it whether the problem improves.