Ribbon Stuck At Loading Only When Using VPN??

Hey SharePoint Fam,

Just ran into a very weird issue that I am not sure where to start.  Basically the ribbon works 100% for myself and all users at the office on the network.  We have vendors/contractors that vpn using sslvpn and they are totally unable to get to the ribbon or click the add a document link.  The ribbon just stays at loading and the add a document link does nothing when clicked.  I logged into SharePoint with my username which has full admin access and got same issue when going the sslvpn route but no issue here on the network at office.....I enabled the allow dns suffix setting and did a flush but still no luck..

thanks for any help