[1903, au] Always-On VPN - DNS Suffix Issues

[CHiLL]

I've been testing Microsoft's Always-On VPN connection for months and generally it's been sucessful. However I noticed that when the VPN profile is installed on a machine, it is changing the DNS suffix on both the Ethernet and Wi-Fi adapter. The DNS suffix usually defaults to 'Append primary and connection specific DNS suffixes' and it's been working correctly for years. However when the VPN profile is installed, it is being set to 'Append these DNS suffixes (in order)' and shows our domain URL in the list (school.bham.sch.uk). This means that the client is trying to use the school.bham.sch.uk DNS suffix to make DNS queries instead of the normal school.local. This occurs immediately as the profile is installed and not even connected. Our profile is configured to not auto-connect when it detects it's connected to the company network ('Connection specific DNS - school.local).

 

I'm using SCCM to deploy out the VPN profile and can't fathom why this DNS suffix is being changed. The only thing that I can see that comes close is the server list on the Connection tab of the VPN profile in SCCM. This has been configured as the VPN's Internet address (vpn.school.bham.sch.uk). Do I need to specify my internal DNS FQDNs here too?