Isaac Sim “Add Nucleus Connection” failed

Hi,

I have successfully started a Nucleus Server on an Ubuntu machine.

However, when I open Isaac Sim on another Ubuntu machine (Host A, with a different IP but within the same network) and try to connect using Add Nucleus Connection, the connection fails.

On Host A, I can access
http://<server-ip>:8080
from a browser without any issues and log in successfully.

Isaac Sim version: 5.1

Thanks in advance!