Double nat packet blocked

[scatt]

Hi guys,
i have a problem with double nat in my pfsense.
I have 2 wan, in one of the two i have a public address for the pfsense interfaces and everythingwork well, on the other i don't have a public ip so i set the router and the pf interfaces on 172.16.1.x, i have enabled the automatic outbound under Firewall->NAT and i have NOT cheched the block provate networks on the wan interface setting.
The problem is that i keep having some packets from my pfsense to the internet ( TCP:A and TCP:PA mainly) filtered by "Default Deny Rule",and this cause a lot of problems.

Looking on the forum the double nat should be well configured, so i don't know where to look at the problem.