The TCP port '8080' is already in use by the u2dcache->port configuration

I want to use "Webserver Protection" on a server that has the website on port 8080 (I cannot change this).

But when I try to configure "Real" and "Virtual" webservers to use port 8080, the system come back with:
"The TCP port '8080' is already in use by the u2dcache->port configuration."

I have gone to Up2Date configuration and have changed the port there from 8080 to something else, but still, it comes back with the same message.

How can I fix this so I can use port 8080 for Webserver Protection?

Thanks,

Rodrigo