WP redirection doesn't allow access to 8008 port

Hi,
I’m trying to make a test updating my php version and my hosting creates a sandbox to make this sort of tests without interrupt the production site. This sandbox is accessed by http://www.example.com:8008 port.
However, there is some redirection in the code that doesn’t allow connect with this port, it always redirect to the real page.

I’ve checked my htaccess file and the redirection isn’t there.
I think WP is redirecting all ports to the main address.

How could I solve this in order to gain access to this port? (without broken the live access)

Thanks