Roku Streaming Stick not connecting to the netwrok

Two months ago, in August, I set up an Insignia TV with a ROKU stick, and it was working fine. I was away for two months. Now, when I turn on the TV, all I get is a "Not connected" screen in a "Searching for wireless networks" loop. Just an endlessly spinning circle on the Wireless scan screen is all I get. Both my phone and computer can still see plenty of available wifi in the same room where the TV is located, but the ROKU stick can no longer seem to find any. What could cause the ROKU stick to lose its ability to find a connection? Can this problem be fixed?

What's the model number of your stick as displayed under Settings->System->About?  Is it one of the sticks that uses a special USB cable with the Wi-Fi module embedded in it?