From Android 10 to Android 9

[rameshnatarajank]

how to go back from android 10 OS to android 9 OS in samsung galaxy note 9

Well possibility is there or not

[chintan2304]

no its not possible

[Anonymous]

without root not possible bro

[Dilli]

you can do it externally by following few youtube videos.

[RakeshKuParida]

no you can't downgrade

[vinayshah]

you can do it with a software called ODIN and download your country region firmware 9 files.