Relative url in omnibus gitlab 8.5

We are using gitlab 8.5 with omnibus, when trying relative url from here

http://doc.gitlab.com/omnibus/settings/configuration.html#relative-url-requirements

Something not quite works, so in the generated page the links with assets are shown as broken, this was an upgrade from gitlab 8.0.4, any pointers on how to debug it?

Cheers,