Yep, Like what I said,
Sony restricts the upgrade system files to be the latest version.
So, I downloaded the latest version and saved it to a flash drive.
It worked fine.
YES.
I'll save the update file to PS5/UPDATE/PS5UPDATE.PUP
I downloaded update file through the link you posted and I did try updating and reinstalling options.
It didn't work,
But the latest version(20240108) will pop up with a new toast, which allows me to update.