Not sure who is at fault but some games from the PS4 are being patched to not be playable on the PS5. Konami seems to be unwilling to let players of to work on the new PS5. That is not very consumer friendly at all.

Ever worse is that the game is not on the Playstation store. So this means the game is being mired with the PS4.

Most likely some licensing problem is in the way. This is the reason for some games disappearing on Steam etc. One PC game, Prey (2007), claimed no more keys are available, which is nonsense as more can be created easily.

One more reason to avoid the PS5 ecosystem.