chatmandu

Your traffic prioritisation rule is incorrect. You've got it the wrong way around. 
You need: 
TCP/UDP
Source Port = 1024-65535
Destination Port 3074:3079

I've performed a fresh wireshark capture and this is what I've found.

The game traffic connection is initiated by the CoD server inbound to the gaming device. 
The destination port internally is 3074 and the source port (internet) is random. 
The gaming device responds using the same ports. 
 
On a 'normal' router (e.g. Cisco), you would need two rules for QoS
Outbound packets from gaming device to CoD server.
Source IP = gaming device
Source Port = 3074
Destination IP = 'any'
Destination port = 'any'
 
Inbound packets from CoD server to your gaming device. 
Source IP = any
Source port = any
Destination IP = gaming device
Destination port = 3074
 
DumaOS doesn't allow you to specify the source and destination IPs for the QoS rules, so it isn't clear how the rules are applied. 
You may be correct that Source port = 3074 and Destination port = 1:65535 works best with DumaOS. 
This is what I previously configured on my Asus router and the packets were correctly marked: 

 

Wrong. 
Port forwarding opens up the destination port on your firewall. It will allow connections from any source port to that destination port. I can't believe you're still struggling with something so basic, but running your mouth as if you're educated. 
QoS is completely separate configuration from port forwarding - but you're prioritising the inbound traffic, that's been permitted by the port forwarding, and the outbound traffic originating on your gaming device. 
"get off the forum then instead of giving bad advice..."
Quite. 
NetdumaOS only has one rule that is supposed to match both inbound and outbound traffic. I'll say it again:
Protocol = UDP/TCP
Destination port = 3074
Source port = any 
Class = gaming/voice
That should be all you need, unless NetdumaOS is badly programmed and they've got their source and destination ports programmed in reverse. 
 
 
 

Anybody that states a QoS rule is the equivalent to placing a device in the DMZ, and then refuses to accept their mistake, clearly knows nothing about networking. 
With regards to the other suggested rules that have been posted, the destination port will always be static (i.e. 3074). The source port is assigned randomly on a per connection basis. This allows the destination device to keep track of all the connections on port 3074. If you're building a QoS rule for CoD, then it should be destination port TCP/UDP 3074 and source port 'any'. That's it. End of.