I have Surface 2017 and I also experienced problems with connecting via Ethernet. I tried multiple adapters and none worked particularly well. That being said I also have Mac Pro with Gigabit Ethernet end I still never saw more than 450 from Comcast, and even that was sporadic. At home, I ended up dropping Comcast for Verizon and I now get 980 down and 840 up. Interestingly, I moved the Comcast gigabit service to my vacation home and the service was closer to the gigabit, but only with their router. However, that speed has recently fallen into the 500 and 600 range. Comcast is tying to force the speed over old coax lines and outdated servers and nodes. Their older infrastructure just cannot seem to support the gigabit speed. The older your neighborhood the worse it seems to be. The number of people with gigabit also seems to effect things. My vacation property is at the beach and in the winter the speed is between rhen in the summer when people are using their vacation properties. The entire Comcast experience has been very frustrating and disappointing. If Verizon had service where my vacation property is located, I would definitely make the switch.
