Thanks for your reply, i’m gonna use some words from fulvio in other post:
The problem is that the QoS classifier works only for the forwarded traffic (bridged and routed). The classifier acts in the FORWARD chain (mangle table). Instead, if the transparent proxy is activated, it redirects the packets to a localhost daemon during the POSTROUTING. This process forward the requests to the destination web servers in the OUTPUT chain and hence the FORWARD one is never used.
I think that’s the reason for the rule that i applied but correct me if i’m wrong please. Thanks for your attention.