Is your Xfinity WiFi router operating on 2.4 GHz? Some new installations may be set up as 5 GHz only. If you don't have a 2.4 GHz network, your Roku Express won't connect, since the Express is 2.4 GHz only.
And, if it is using 2.4 GHz (many networks use both 2.4 GHz and 5 GHz), ensure it's on channel 1, 6, or 11.
DBDukes Roku Community Streaming Expert Note: I am not a Roku employee.
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