Firmware 9.00 is highly sought after because it is the latest version compatible with specific "jailbreak" exploits.
It’s best to install specific firmware via Safe Mode.
Firmware 9.00 for the PlayStation 4 is a major system software update released by Sony. It’s particularly notable in the modding/homebrew community due to a WebKit vulnerability, but for most users, it remains a standard stability and feature update. This guide will walk you through downloading and installing version 9.00 on your PS4.
October 24, 2023 Subject: PS4 9.00 Firmware: Download, Installation, and Update Details
Since Sony only provides the latest firmware on their official site, you must find version 9.00 through reputable community archives.