Hi Mooncake822,
Sorry for the delayed response, we've been wracking our brains over this issue!
Could you firstly check that both the PS4 and PS5 are on the latest updates of the game? If for some reason the PS5 is on an old version, the sabe won't work. To check this, boot the game and look in the top left of the main menu screen. You will see a series of numbers that correspond to the build number.
If you could also try the transfer again and let me know the date and time (including your time zone) that you receive the error, we can try to look in our error reporting systems for your exact issue.
Could you also let me know how you have attempted the transfer?
Thanks for your patience,
Chizel