Unequal cpu cores usage - RB1100AHx4

Hi,

I have RB1100AHx4 running as PPPoE server with 30 firewall rules and simple queues (one per pppoe client).
Currently there are approx. 570 active pppoe sessions.

Everything works fine but… cpu cores usage is unequal.
CPU0 usage is high - at ~ 80% and growing with traffic
CPU1-3 maximum usage is 20-22%

Is it possible to equalize CPU usage on all cores?
MT version 6.40.6(bugfix)

Regards
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