Cisco AnyConnect Client Connection Issues

[Heathy65]

I have OPNsense running as my main router in my SOHO with clients on a directly connected LAN.  Downstream from the OPNsense router there are two Ethernet WAN connections.  These are each connected to VDSL routers (via 2 separate private networks), so I have doube-NAT.

Currently I do not have any load balancing enabled so all outbound (Internet) traffic is using a single WAN connection.

All is good with a single exception.  I have have a work PC which has a Cisco AnyConnect client which is used to establish a VPN towards an external destination.  This VPN client always prompts for the credentials but rarely establishes a connection.  I would say that 1 connection in 10 is successful, if that.

If I connect from one of the private networks 'behind' the OPNsense router then I have no such issue, so I assume it's something within the OPNsense configuration which is causing the issue.

Thoughts appreciated.

[chemlud]

Can't you have the VDSL stuff in modem mode?

My crystal ball says: it the firewall rule. 3rd from top on LAN....