I installed this router over 15 months ago, and only recently have begun to speculate it is causing a problem connecting through the 5GHz channel. I'd appreciate troubleshooting recommendations. I have an HP Pavilion desktop connected with Ethernet to the router. The router plugs into a wall port with Ethernet that connects to optical fiber in an entrance panel off the storage room. The optical fiber connects to a switch in a central location in my residential community and from there goes out by fiber optic to a contracted ISP. We have a professional Network Admin who oversees operations. I have two other computers that connect to the router wirelessly. I have e-mail and web browsing assigned to the 2.4GHz channel and the 5GHz channel is set aside exclusively for a Roku 2 that connects wirelessly to the router and by HDMI to a TV. Beginning several weeks ago, I have encountered two problems: 1. The Roku either takes an exceptionally long time to connect, say, to YouTube or PBS, or it fails to connect and reverts to the home screen, or it gives the message "No Connection." 2. The router sits next to my computer screen so the front panel is easily visible. I notice that sometimes the icon for the 5GHz channel is either dimly lit or not lit at all, although the icon for the 2.4GHz channel is lit bright and steady. Sometimes when the Roku does not connect I find the 5GHz icon not lit, but not always. The icon might be brightly lit but the Roku will still not connect. One evening when I let the "No Connection" screen stay up the Roku light blinked and blinked - and finally got a connection. Once the Roku has connected, I usually have a steady signal, but occasionally I get the message "Loading . . ." or experience a very short loss of sound or a blip in the video. If go out to the entrance box and plug a notebook computer with Ethernet directly into the port on the ONT, I get a fast and steady connection out to the Internet. The Network Admin says there is plenty of bandwidth so it seems unlikely this is a form of signal starvation in his view.
I am running Windows 10 on the HP Pavilion with Norton and Malwarebytes as security software. I run System Mechanic occasionally and have never found a problem beyond "clutter" and a query about deselecting items in the Startup folder. My default browser is Chrome, but I occasionally resort to Edge. I am not aware of any other operational difficulties with my desktop machine, the second desktop machine (that connects wirelessly) or the notebook computer with Win 7 that connects wirelessly.
I turn off the router each evening and turn it on in the morning so that it is not ON continuously and requests a new address every day. I usually leave the Roku turned on since there is no ON/OFF switch.
Thanks for insight into this and recommendations for a fix.