Fasttrack

Greetings, I hope you can help me clarify a problem, it happens that I have a 2116 doing nat with two providers and route brands, to optimize and lower processor usage I have activated fasttrack for established and related connections, when activated it works with one of the wan, but not with the other one, when I activate it I can see a packet drop on that wan.

http://forum.mikrotik.com/t/problem-with-fasttrack/177791/1