Thanks for your helps. Now it's worked as it should. perfect ads blocking. its seem we can't use system/etc/host in Nougat directly, we have to use systemless host file because i have to turn on systemless host in Magisk setting. Right ? it mirror host file in system/etc to /magisk/.core if i turn it off it doesn't block ads.
"Good judgment comes from experience, and a lot of that comes from bad judgment." - Will Rogers