I'd be happy to take a closer look to see how we can help. Do you receive an error code or message when connecting to the network? Did you try to connect the device to your home network or to the router?
Furthermore, if the affected device is either a Roku Express or Roku Premiere, please note that they are only compatible with wireless b/g/n networks on the 2.4 GHz spectrum. Ensure that your hotspot is broadcasting a 2.4GHz Wi-Fi network for the device to connect to. You can check your device model by navigating to Settings > System > About. If you are getting an error code or message, refer to this link for common Roku error codes and their recommended actions: How to connect your Roku device to the internet using Wi-Fi or Ethernet.
I am having the same issue. Two days ago after a stormy day, all of our Roku devices stopped connecting to the internet. I've done all non-pro steps in the articles several times but no joy. I've tried both the Xfinity hotspot plus our own netwk. A couple times it showed error code 14.30 It fails at "wireless connection" every time. Tablets, phones & computers still stream when connected-- so it's not the router or signal. Network speed testing seems fine now (Xfinity did some tweaks). Multiple devices have the problem-- a TCL Roku TV, a Premier and an Express. It's not a power surge (we got the whole house protector-- this is Florida, plus no issues w other devices now). Thoughts? Suggestions?