Could someone help explain this CPU Load please? GIG PPPOE

I got GIG FTTH and they use PPPOE, I know that PPPOE is handled by 1 core but it’s reaching 100 percent, is that an issue? also, if I enable a Simple Queue (SFQ as the upload is 60mbps and get bloat ) I still got near 900mbps, but what’s puzzling me is that the same core remains at 100 percent with the others nearly idle ( with a queue on or off), shouldn’t the queue use a different core than the PPPoE? or is it using the same core?
Router rb4011

Thank you for taking the time to help me understand this.

Regards
Chris
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