We have tested Goodcloud access in our office before installing the router in a client site and it was working well. On moving it to a client location Goodcloud access seems to not work - i.e. the router appears offline in Goodcloud. Internet access seems fine when we are accessing internet through the router (and you can visit goodcloud.xyz and browse) but clearly the router cannot reach goodcloud itself through a VPN.
What addresses/protocols need to be unblocked for this connection to work?