Manage out Always On VPN client

Question

I have Always On VPN working well with split tunneling and routes to internal subnets defined in profile xml. Clients can connect and access internal resources and the VPN server can ping/SMB to clients. The problem is that other internal servers cannot connect to the clients.

On a test internal server I have added a static route to the VPN subnet with the VPN server IP address as the gateway:

route add 10.10.0.0 MASK 255.255.252.0 [VPN server IP]

The Test server knows the next hop:

Test-NetConnection 10.10.0.2 -DiagnoseRouting

ComputerName              : 10.10.0.2
RemoteAddress             : 10.10.0.2
SelectedSourceAddress     : [Test server IP]
OutgoingInterfaceIndex    : 11
SelectedNetRoute          : DestinationPrefix: 10.10.0.0/22
                            NextHop: [VPN server IP]
RouteDiagnosticsSucceeded : True

I have checked firewall rules on client and server and they should allow the connection. I have even tried disabling the firewall entirely on the VPN server and VPN client but still nothing seems to reach the client.

Do I need to configure something on the VPN server to allow the traffic from the internal network to be routed to the VPN clients?