I need to install android 8.0. I have Android 9.0 (patch 09.2020 update). I can only install android 9 (install Odin). Is Android 8 installation blocked? Is there any way to root j3 2017? (Android 9.0 patch 09.2020 update).
Hey there. Samsung doesn't allow downgrading to lower versions. If you try doing it through Odin, you may end up bricking your device. Or if you do end up getting it installed, some things in the OS like camera, sensors, etc. may not work. Hence, it isn't recommended to downgrade.
For rooting, you can take a look at the thread below to check if your model number is listed and try.