L2TP connected but not passing traffic, internal or external

[Mowser]

Hi everyone. Been battling with this issue all week and can't make any sense of it.

Here's the situation. We run PFSense at our office. We have a remote worker (covid) who needs a phone. We have a Avaya IP500 system here so the IP phones can't connect through the external IP addresses and the traffic has to be handled through a VPN.

I have setup the L2TP server here:

WAN Firewall Rules:

L2TP Firewall Rules:

On the client side I can see that it is connected

But I can't ping the router at all, or access the web UI. Already enabled the remote management to 0.0.0.0/0

If anyone can offer any help, that would be amazing. Been searching everywhere for answers and tried everything I can find but no luck.

Thanks in advance!