I rooted on my S8+. I used the app root checker to check that it's rooted. I was attempting to block ads by hosts files with this tutorial
I attempted to copy the hosts file to my pc, changed it, and pushed it back... got:
adb: error: failed to copy 'hosts' to '/system/etc/hosts': remote couldn't create file: Read-only file system
hosts: 0 files pushed. 62.2 MB/s (456580 bytes in 0.007s)
I then attempted to do it by following this tutorial which uses apps to change the files
I did change the host file permissions to -rw-rw-rw-
Then I tried to use the editor to add some DNS but I was unable to save the hosts files once again. When I tried to save it, I got a Toast saying root permissions were given to the text editor.