When you purchase the full version of DEAD OR ALIVE 6 Last Round for PlayStation®5, the game is designed to install the free-to-play base version along with the usage rights for each character, Story Mode unlock rights, and other DLC data all together.
If a character that should be available in the full version cannot be used, or if certain features have not been unlocked, it is likely that some DLC has not been applied correctly.
Please try the steps described in the following article: