Hi,
Not familiar with Playstation, but I'm pretty sure it's because it's two different versions of the game (the one on PS it's the base which doesn't include the expansion). A bit like The Witcher 3 and The Witcher 3 Goty/Definitive Edition. Likely achievements aren't shared and won't be transfered.
If you're able to play the PS Plus version, launch it, link your CDPR account (if possible), load the last save, create a new save and let the game uploading it on CDPR servers. Then launch the ultimate edition, be sure it's linked to your CDPR account and check if the save appear.
Welcome to CD PROJEKT RED Technical Support! Here you will find help regarding our games and services, as well as answers to frequently asked questions.
support.cdprojektred.com