I just had 3 clients in the past week start experiencing this issue. The users all had Netgear wireless devices at home. I believe they had Orbi devices. See if the users can use their mobile phone as a hot spot and see if the issue goes away.
I would also check their TCP/IP Advanced settings for the VPN connection and see if "Use Default Gateway on Remote Computer" is set the way you want and make sure there is not a IP subnet overlap.
I noticed at the end of the script there is a command to create a registry for connecting to a MX behind a NAT. You could try just running this command and rebooting the client and see if this resolve the issue.