CCR router, with v6.1, queue tree does not work well, with mangle.
I have some mangle rules in forward chain and queue tree with PCQ.
Some queues process packets slower than others, the buffer has more packets. If I change priority and give better priority to the problematic queue it works.
The problem is with the queue which has more traffic than others.
The router processes about 400Mbit of traffic and processor is 12%.
It is not a bandwidth problem, i have not put anything Limit-Max or Limit-At.
If I enable/disable queues it works well for some time than again it give problems.