Hi there,
I have the exact same problem but can’t manage to fix it. Mind you, 2 days ago, it was all working good! I have roku ultra and a router to-link ax11000.
I tried rebooting the router then roku. Reseting the connexion of the roku. Using my phone as hotspot(this worked, and i was able to complete the setting after i return roku to factory setting). Then I change 2,4 connection to 20mhz channel 11 and b/g/n mode. In 5ghz, i change to 40 mhz chanel 161 and it shows 802.11a/n/ac/ac mixed as mode. I deactivated whatever firewall and security option available and I reserved an ip address to the roku. Oh and between each of those changes, i rebooted both the router and the roku. In one occasion, i saw internet speed on the information screen but it lasted only couple of second. Internet is working otherwise and my isp is telling me that roku should know the setting my router should have in order to work. I am actually beyond annoyed with this now really expensive useless gadget. Did I mentionned that neither the router nor the tv were moved ans the one time I saw the internet speed, it was at 102mps. Please please help me!
