Hi
Welcome to the Microsoft community.
Your problem may be caused by DNS error. You could find its IP address on another unrecognized computer, and then use IP to access it to see if you could recognize and connect? Or did one of your computers become a public network due to reinstalling network properties?
At the same time, you could try a network reset, reset all networks and reconfigure network sharing settings to see if the problem still exists?
Looking forward to your further news.
You are welcome to reply to this topic at any time, and sincerely thank you for your support of Microsoft products and services.
Best regards
Derrick Qian | Microsoft Community Support Specialist
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