Long story short…. First check your router settings.
I found that my router had somehow had INTERNET TRAFFIC METER ENABLED.
Maybe a firmware update, not sure, but as soon as I disabled this my download speeds almost doubled and upload speed increased also.
My modem is a Technicolor CGM4140COM is in bridge mode and I use a Netgear Nighthawk R7960P to manage my internet/network.
ROUTER SETTING INTERNET TRAFFIC METER
ENABLED 400’s mbps download (DL) and around 30’s mbps upload (UL)
DISABLED 900’s mbps download (DL) and around 40’s mbps upload (UL)
With internet traffic meter disabled in my router I speed tested using Xfinity’s speed test https://speedtest.xfinity.com/ with results of 900’s mbps DL and around 40’s mbps UL via a wired connection to a gigabit switch straight to my gigabit router. I also speed tested using Ookla https://www.speedtest.net/ and Ookla’s results were slightly slower with results of 800’s mbps DL and around 40’s mbps UL.
Hope this helps someone!
Thanks for posting !