Xfinity says I need to contact Netgear as I'm not getting advertised speeds

I was subscribed to the 150mbps plan and I was usually getting about 180 on a speed test. For $20 more I upgraded to the 300mbps plan. I'm still getting the same 180mbps. Upload is the same as well.

After restarting the modem 10 times and 3 phone calls with Xfinity, they told me the Netgear is the issue and to contact Netgear. Their level 2 folks said that there may be a setting I might need to change.

I would appreciate any advise. Thanks to all for looking and for your help.

(I've tested 2 machines - i3 Sky Lake with 8gb ram and another with 16gb ram. Both are hard wired using cat5 directly into the Netgear.)