paraview stuck while establishing connection to pvserver on kubernetes

i run pvserver in kubernetes side with the command:

DISPLAY= pvserver --server-port=30111

in the client side i run:

kubectl port-forward svc/job-0 30111:30111

when i try to connect by paraview to cs://127.0.0.1:30111
the server side say “Client connected.”, but, i stuck with the message:

Establishing connection to ‘my server’ Waiting 20 seconds for connection to server

and i have no chois but killing the paraview session from the command line.

(version: paraview 5.11.1)