If that Xfinity router is 5GHz only (which would be unusual) then your 3900X won't work. It probably also supports 2.4GHz, but they may not have enabled it because all ISPs seem to be idiots.
The 3900 is a single band device, and doesn't support 5 GHz. If you can log into your router, see if it has a 2.4 GHz radio that is disabled, and if so turn it back on. Otherwise, yes you need a Roku with dual band support, such as the Stick, Ultra or one of the sound bars.
You ha e to totally reset your roku from scratch. It must be a bad update. After I set everything back to default and reset it worked fine.
If you folks can access and adjust your WiFi routers, then try forcing it to use 2.4 GHz channels 1, 6, or 11, instead of auto.
Worth a shot...
Sadly, for those who have older Roku's, You will find that they will be good for nothing except paper weights! Why is this? Because Roku can't make money if people doesn't buy new streaming boxs/TV's! I own all from Roku 1 to 3, to Ultra 4k! My Roku 3 box, top of the line 3 that is, worked fine last year, then one day I went to use it , after and update I believe it was, and now it is starting to act like the models before it did was acting, before they went south on me. they wouldn't open an app, when and if they did it took forever to load movie, then after movie started after a few minutes it stopped playing threw an error at me if I remember right. Why is this? Because Roku, has filled it with so much **bleep** ware, it's memory is tanked. and without enoug memory, apps are worthless. The Roku 3 will be next in line for the paper weight stack it may already be there, haven't used mine in awhile. Sad that we pay good money for these things, and ROKU stoops to this level to make more money off of us. But hey, Samsung, Sony and all the others are doing it as well! I guess it is alright for them, if they can sleep with it, but if I done that to those that made me rich, I would would bury my head in the sand and let the world go by. Just stop buying from them, I won't give them another dime of my money, don't care if I have to go back to days of old and slap a DVD/ Blu Ray into my player, don't have to worry about someone sticking it to me, and DVD/ Blu Ray looks a lot better any way aye? Regards!
Roku could not give a **bleep** less about this pervasive problem Roku owners have had for years.
It is 100% a device problem. I will never buy another one.
Yup. My Roku 2 had ZERO ISSUES. I only upgraded to express because HBO and Hulu were no longer supported.
100% a device failure.
Roku has sold five different models called a Roku 2 (with some added letters on the end). Only two are still supported, and even the newest version is now over 6 years old. Electronics can fail, sometimes in far less than 6 years.
I have the same problem that just started a couple of weeks ago. ROKU is now useless. It can't find my wifi, then if it does, it can't find the internet. My phone and laptop have no problem finding both. It spins for 20 minutes, then all of sudden, it works for 5 seconds, then starts spin mode again. I have restarted the router and the roku, and that does nothing. I am using HDMI stick.
There certainly seem to be a lot of people with the same problem and ROKU does nothing