Greetings!

I have a strange issue that I can't seem to find others having.  I have a 2011rb installed at a tower location where we use hotspot for authentication.  ports 6 7 and 8 are in a bridge, the hotspot is configured on the bridge interface.  However, there is another tower (let's call it tower B) that back hauls off of port 5.  And every couple of days, all of a sudden the customers on tower B can't fully load facebook.  The site will load, but adds, pictures, videos etc will not load at all.  It's hard to imagine that facebook would be the only affected site, but it's the only we are currently aware of.  If I disable and then re enable the hotspot on the first tower, everything starts to work just fine on tower B for a few more days until it happens again. 

I have tried the following;
upgraded firmware
issued the "system routerboard upgrade" command and then rebooted after routerOS upgrade
adding facebook.com and it's other variations to the Walled garden (although that would be stupid to have to do)
Added an explicit allow into the firewall

Any help would be very appreciated!
Let me know if there is anything else I can tell you about our setup.

Thanks in advance!

Run hotspot separately on both router A and router B