Rasplex not finding the local server anymore.

I have a problem since a few days.
Rasplex do not find the server anymore.
I can’t do anything.

Rasplex is properly connected to the network (i can ssh rapslex from the plexmediaserver).
Plexmediaserver is running ( i can watch video from android or ios app).

any idea to troubleshoot ?

Re-signin? What PMS and Rasplex versions are you running? Does your PMS have a firewall? Lots of variables here.