Why is DFS not available after VPN IKEv2 connection?

Question

VPN

There is a domain based on Windows Server 2012, but the domain level is 2008 R2 with DFS. In our organization, one domain forms one tree, forest, site. That is, there are no bells and whistles, only one office. There is a third-party organization that has nothing to do with ours, but you need to connect to IKEv2 VPN to this organization in order to be able to work with the resources of this enterprise. When VPN is connected, DFS, which is connected as a network drive, is no longer available to users. I cut off the VPN everything is fine. In the VPN connection settings in the additional IPv4 parameters, the IP address of their DNS server is registered.

Answer 1

First of all look at routing.

Answer 2

But do your users use the gateway on the remote network as the main one?