Hi
First, I don't see in the new configuration you shared the 8080 port statement as the first output you shared .
This (J-web) should work only if you go through the browser to http://<switch-ip>
1- So if you need to reach the switch over the 8080 port, you need to configure the following:
# set system services web-management http port xxxx
2- If it work with or without the port statement , try to restart the httpd deamon:
> restart web-management
if still not working , share us the follwoing:
> show system processes extensive | match http
And while you're trying to reach over the J-web switch share us the output of:
> show log httpd.log