Firewall device running IPSec VPN cannot traverse VPN, but other hosts behind it can

I have a hardware device (netgate brand) that acts as the firewall/router for my LAN.

It has an IPSec VPN connection to AWS VPC.

• All hosts in the LAN can traverse the IPSec VPN successfully. Traffic flows back & forth fine.
• The firewall device itself cannot.
• All routes look ok
• No security groups/firewalls are blocking anything at all right now during testing.

Is there any special trick or rules that generally need to be put in place to get the host that is running the IPSec tunnel itself to traverse the tunnel?