No. You cannot downgrade a PS4 firmware by simply plugging in a USB drive with older software. Sony explicitly blocks older firmware installations through the console's operating system to prevent piracy and security exploits. Can it be done via hardware?
Sony’s security architecture makes firmware downgrading exceptionally difficult. Here’s why "sistrodowngradeps4" likely doesn’t exist.
Your situation likely falls into one of three categories. Here’s actionable advice for each.