Server not found

I have a problem,
Since yesterday I can’t find my PMS and when I connect to plex, in the server list, there is only a message “Server not found” my PMS worked well since one year and today it can’t find my own server. I have installed the latest version.
I tried to access it with the server IP and same thing. I Uninstalled/Reinstalled it and same thing.
I don’t know what to try.

https://support.plex.tv/hc/en-us/articles/204604227-Why-can-t-the-Plex-app-find-or-connect-to-my-Plex-Media-Server-

https://support.plex.tv/hc/en-us/articles/204281528-Why-am-I-locked-out-of-Server-Settings-and-how-do-I-get-in-