Android 9 at huawei p20?

My cellphone was created for misterious purposes Automatically updated by andriod 8.1 oreo to these damn android 9. Apart from the fact that this happened against my will, my cellphone lighters more quickly. I guess someone like man can get this android 8.1 oreo again, thanks in advance 😊.

Define "chop off"

So in comparison to the old Betrysystems the battery life was already back and the mobile phone also started to heat up.

Best reset to factory settings, android 9 you will not go back.

Ok, thank you