I'm guessing that you don't have anything in the firewall blocking this at the mo?  Some providers block inbound traffic to IP's distributed so it might be worth checking with them before digging around to much.

In theory you can add wildcards in /ip hotspot walled-garden  eg *.netflix.com or *netflix*.  You would need to add other domains netflix uses too.  There are known problems with this and HTTPS though.  This thread is for Facebook but the principle is the same and it discusses some of the problems /...

I was wondering if anyone knows what determines the TX Power set on Mikrotik's SFP+ modules?  I've got a link where it's suddenly dropped and as a result the other side can't see me any more.  Testing out the link with loops that's defiantly the issue.  Is there anyway to manual over-ride it?   Also...