This started happening on my Android devices last night. Unfortunately, it cost me an hour or so of sleep because I started scrambling around changing my wifi network password then updating all the umpteen devices that connect to it. Then, when I got to work, NMS reported my work wifi as compromised as well! Seriously?!??
Turns out, it's a false positive alert due to a bug introduced in an application update that was published last night. It's since been fixed.
Norton Community post from Norton itself reporting the issue and its eventual resolution:
https://community.norton.com/en/forums/nms-wifi-security-network-compromised-alert
To fix the issue, go to Google Play, search for Norton Mobile Security and update the application. The annoying alerts should go away.
