You probably opted to sign out all devices when you reset your password. That includes the server itself. You’ll need to re-claim it, so the regular Plex apps can see and access it.
Can you still access your server using http://127.0.0.1:32400/web on the same machine?
https://forums.plex.tv/t/new-claiming-requirement-for-windows/839096/1
If you can’t see the server at all… is it still running?
You should see the Plex Media Server‘s icon in your system tray.
