jQuery download fails in login page for single user

Probably not an Auth0 issue specifically but we have a single user who, when he is redirected to the Auth0 page, the jQuery download fails and as a result the login dialog doesn’t work. No action happens when clicking any of the links/buttons etc. This happens with all browsers that have been tried. Other users have no issue, including other users using the same network connection e.g. it’s not some issue with the router/firewall. Has anyone seen this before? Any suggestions on how to troubleshoot?