Cannot connect to the agent on the clound

Hi,
I have successfully created and installed new agent on EC2. The loadUI agent is running.
However I cannot connect to that agent from the Load UI application installed on another machine.
It shows the dark red little orb on the top left. I use the AMI's public DNS and port 443 as specified in the doc.
I changed the security settings of the agent on EC2 to allow https on port 443 but it still doesn't work.
Can anyone help, please.

Thanks,


Olivier.