MikroTik and SurfControl

I just put in a MT system to control 3 networks… long story short. the system I use (Surf Control) web filtering no longer seems to function right.

it send back
Error 502: failed to receive headers in response

instead of its normal HTML page that says your busted. (blocked site)

and sometimes i get DNS errors instead. Any ideas?

The problem only happens on the network using HotSpot. Other connections work fine.