point me to "downdrade 10 to 9"

[atifsh]

since i get 10 my loudspeaker has weird sound like rattling and very poor, it was fine on 9.

 

[Ashish.akc]

Don't know if this'll solve your problem but here is it https://forum.xda-developers.com/oneplus-5/how-to/op5-collection-unbrick-tools-t3898870

 

[harsheshsachdev]

Download latest stable on android 9, i.e. 9.0.11. install it through stock recovery. First boot won't work properly, boot to recovery wipe everything and done. Everything will work fine. just that OTA notification will be a pain in the ***