Ultimately, even with some of the slowest HDDs, Far Cry 6 shouldn't take too long to load, so if the issue with the 'Warm Up PSO cache' message persists, there might be some bigger problems behind it, in which case you should check the health of your drive. If none of these options was of help to you, trying contacting Ubisoft support directly and see if they can help you.

Check out Ubisoft's official social media pages to see if the problem might be on their side, something like a server outage might be the cause of this issue.Finally, try to restart your PC and then run the game again to see if it will load faster this time around.If the game still loads slowly even while on SSD, try to verify all the files via Ubisoft Connect, as there might be an error that has occurred during the installation process.

If you have an SSD, try reinstalling the game there, it will drastically improve your loading times.

If your game is installed on HDD, this will make the loading process significantly slower.

Fallout 4 textures take forever to load