@r4mzy thank you soooo much!! I've given me the right direction to solve the issue
I was accessing the aggregate site on port 8080 as I've run the cmd
aggregate-config --fqdn auto --http-port 8080
but the request starting from the site was not updated to match the port, so they went through 80.
Setting everything on port 80
aggregate-config --fqdn auto --http-port 80
solves the issue.
I'm only wondering what I should do to set it on a different port...
Thanks to all.
Best,
Chiara