Slow LAN speed after upgrading to 1.2gb and installing new equipment

I have a 1.2gb plan. Just installed equipment. No issues detected by bot chat. 900mbps max. I should be getting closer to 2,000 mbps. Upload speeds are as advertised.

I see others on this forum with the same issue. No solutions other than essentially "It's you, not us."

So before support says anything...

• I run malware scans weekly. I built my computer and take good care of it. 
• I restarted the modem twice.
• I am connected via LAN
• No, I am not downloading anything else.
• I've tried 3 different ethernet cables

It is YOU, Xfinity. Take some accountability and help me.

As of now I am paying extra for literally no speed improvement compared to my previous plan.