Course doesn't work in the external access (VPN)

The issue is more complex, this client of ours uses Cisco Anyconnect which dynamically creates a token in the URL that makes access to the platform and in the elearning course (integrated in SCORM). The access isn't made by a regular VPN, the technical name is reverse proxy.
It seems to us that the content in Storyline loses the references of some files, but we don't understand why.