Are you getting any error messages or codes like 14.30? If you see that 14.30 code ensure your router's wireless mode is set to b/g/n and not g/n. If you need help with that post back with the name of your ISP (Internet Service Provider) and/or the manufacturer and model number of your router.
@Garrisonsgurl, see if this link helps:
It looks like you need to use an app to manage your settings. Cox is one of the ISPs that's known to have this issue and they should be able to help you make the change.
@Garrisonsgurl, since I don't have Cox I can't look through their app to see where the setting is hidden, but it's probably under advanced Wi-Fi settings. You're looking for something like "wireless mode" and/or anything that references the letters b, g, and/or n on the 2.4GHz band.
Maybe there's a Cox customer that can help?
I too am experiencing this same issue. My ISP is Xfinity and my router is an ARRIS, Model #TG1682G.
Any knowledge you can share with me in regards to my Roku connecting to my home wifi would be greatly appreciated!
The TG1682 on Cox is getting more locked down. Some still are able to make this mode change themselves through the app or web portal, others are not. (options greyed out). In the event you cannot make this change, you will have to contact Cox and have them make this change for you. (Wireless Mode/Protocol on the 2.4ghz band edited/configured to b/g/n).
If available to you, should be under Advanced as mentioned by @renojim, but dependent on your router's firmware revision. To get to Advanced from app--> Connect/See Network/My Network/Advanced/LAN&WAN)
Should have no issues making these changes on the TG1682 on Xfinity. Here is link how to make change from Xfinity as well as walkthrough posting here in Community.
Xfinity / Comcast → ( https://www.xfinity.com/support/articles/change-wifi-mode-admin-tool-xfinity-xfi ) with a walkthrough ( https://community.roku.com/t5/Network-Wireless-Wired-Connections/Error-014-30-stuck-for-three-days/m...)