Can you downgrade your PS4 software?
There is no way to downgrade a ps4 firmware with any legal software. You would have to get a ps4 system with a 5.05 firmware installed. If you obtain that system it would be wise to disable internet connection. That way there will be no updates to the 5.05 firmware.
Can you restore a PS4 to a previous version?
Sony consoles were never designed to be downgraded - once they have a new firmware in them they won't accept an older firmware.
Does factory reset downgrade PS4?
No. Factory resets won't remove firmware updates. You can't, you've basically installed the new OS over the old one and Sony does not allow downgrading. You don't ever need to do it.
When was PS4 9.00 released?
On September 15, 2021, Sony released update 9.00 allowing PlayStation 4 users to access PlayStation 5 trophies, improvements to parental controls and messages feature.
How to downgrade PlayStation?
Which PS4 Cannot be jailbroken?
Can PS4 be jailbroken?
Is it risky to jailbreak?
What is a jailbreak PS4?