Have recently upgraded my Xfinity service to 600 mpbs download and 20 mpbs upload. I also purchased An Arris Surfboard SB8200 Cable Modem and an TP-Link AX11000 Router. Everything had been smooth after a few hiccups early on ( Have had this for about a week ). Running speed tests online usually get 500-600 download and around 20 upload. But last night and tonight it was EXTREMELY slow, like under 50 mpbs and 3 mpbs upload. I am in a small home with my PC directly plugged into router with just a few TV's and cell phones on the network. I have unplugged everything a few times and done all that to no prevail. Just ran a test on Ookla now and am only getting 102 mpbs download and 24 mpbs upload. Any idea for me to find the culprit here? My hardware is more than capable, any suggestions would be grateful! Anything i can run to post here to help would be helpful too. Thanks!