help determining the bottleneck! bufferbloat

[clutchmaster]

ok been running a bare metal with a 3770k and been trying to solve my bufferbloat issues and made a discovery that if i codel my WAN to well below my line speed i finally get an A+ so now im stuck wondering what is the bottle neck in the chain.

A+ bufferbloat = (166mb/s down +3ms) (9mb/s up +0ms) from 24ms 2.5ms jitter
my isp(spectrum) from speedtest = (375mb/s down +80ms) (12mb/s up +2ms) from 27msspikes 500-1000ms
so far ive only put limiter on the WAN port

a couple years ago i got a tech to come over and replace the modem and got lucky and got one of
 there spectrum branded DOCSIS 3.1 phone+internet modems sadly i dont think it support 2.5gb link to the WAN port so my 2.5g nic is wasted oh well maybe ill find one that supports it for free to illeminate a bottleneck there