Gl-e750, tor, dns

I connect to a mobile network, turn on tor, go to any site with a test dns, and always see my real dns, I think this is not normal when enable tor. Or what? GL-E750 Firmw 3.211

What is your real DNS? How is it configured?

For example in windows if you set 8.8.8.8 it will automatically encypt the dns.