Hardware help with prodinfo

[Prince ofhell]

• my friend have upgraded his console for 6.1.0 to 6.2.0
• the console stock on switch-logo
• i read that i have to
• Downgrading Manually from 6.2.0 to 6.1.0 for this guide guide.sdsetup.com/#/manualchoidowngrade
• every thing went normal tell 9
• the prodinfo bis key 0 are failing
• the same keys as a prodinfof are ok
• so what i must do ??