If still having issues, post back with Roku model number (Settings/System/About), your router model number, and your ISP (internet service provider).
Also provide any error messages you are seeing on screen (should include some numbers in the popup error box) and if this is affecting more than one device. If multiple Roku devices, post their model numbers as well.
You can also use a mobile hotspot to complete your setup/activation since you reset (assuming factory reset rather than simple restart), if available to you. Using a hotspot will also help confirm that the device is capable of making a connection.
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