Does it see any WiFi networks, or is it not showing any? Can you turn on a hotspot on your phone and see if it sees that one?
If it can't find any WiFi, and your network is working on a different Roku device, odds are the TV is defective. It can happen with any electronic device. I had a defective Insignia Roku TV that was stuck in a setup loop. Returned it to Best Buy and got a different one (same model), and it's been working fine for over 5 years.
If it was seeing other networks, I would have some different suggestions, but the fact another Roku TV is currently connected to the same network pretty much eliminates a networking issue.
Dan
Roku Community Streaming Expert
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