2 rokus 1 works 1 doesn't. In fact every device in my house connects except the roku express. It sees the network but does let me login(the password is correct). Today I went to the store and purchased a new express and the same thing happened????? VERY FRUSTRATING Yes I have tried rebooting all devices and the modem. nothing changes. It sees the network but will not login. My ip shows that it is there bu not connected too!!
Post your Roku device models, your router model numbers, and your Internet Provider (ISP). Reports that routers from Cox, Xfinity/Comcast may need to have the mode/protocol setting under Wireless Settings to reflect b/g/n for Roku to connect.
With more detailed info regarding your router models and Roku models along with any error codes, can hopefully offer some troubleshooting for you to see if changing some network settings from within your router can get you both up and streaming.
Since you have now split your network and can connect to your 2.4 ghz band, strong possibility that your 5ghz band is/was using an incompatible DFS channel. Under the 5ghz band, the compatible channels for Roku are 36-48 (low band) and 149-161 (high band). Try manually assigning these rather than using Auto if your router software will allow. (Some managed merged/mesh systems) will not allow users to configure their 5ghz).
If you need additional help, please post same requested info from above re: router and Roku model numbers.
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