I recently had to replace my wireless gateway. Ever since, my Roku will not connect to wifi by default. Every day, I get a message saying it can’t connect. Every day i tell it to restart - and voila the connection will work just fine. We have to do this several times a day every day and it’s maddening. The Roku box sits just a few feet from the router so it’s not that. As far as I can tell it’s broadcasting on a 2.4GHz signal.
Do you have Comcast? We have the same problem and it is a real pain in the...well...you know. I have seen on some forums that you have to enable IEEE 802.11b wi-fi on your router to fix the problem. However, Comcast has removed the ability to turn that on.
The cable ISP companies (Xfinity/Comcast, Cox, and AT&T) have router firmware that is the likely culprit and is affecting 2.4ghz devices.
Depending on router, may be able to make changes yourself by logging into your router or using their mobile app if applicable. Otherwise need to call the ISP, tell them to enable the 2.4ghz band if they have disabled it, and set the "Wireless Mode" of the 2.4 ghz band to b/g/n protocols.
The above is only affecting 2.4ghz devices so can also purchase/use dual band (2.4ghz and 5ghz band capable) Roku devices and get around issue, but you should not have to, and the ISP should make the necessary changes so you can use your existing devices.
Roku Community Streaming Expert Just another Roku user... I am not a Roku employee. Insignia RokuTV, Ultra 4660, Premiere+ 3921, Express 4k+ 3941, Streambar 9102