Can't reach the Internet!

[acc]

Hello, I've hit a bit of a brick wall and looking for someone to tell me I'm doing it wrong please :-) I can't ping 8.8.8.8!

I have two subnets that can reach each other: all devices either side can ping, RDP, ssh, everything. 192.168.0.0/24 is a TP-LINK Wireless router running DD-WRT and the other is 192.168.175.0/24 on a Hyper-V VM as opnsense. Both vNICs for the opnsense VM are external: one is shared with the host and is connected to 192.168.0.0/24 LAN (opnsense's WAN interface) and the other is not shared with the host and is 192.168.175.0/24 (opnsense's LAN interface). On the same switch I have a couple of other Hyper-V machines with several VMs all making use of 192.168.175.0/24.

Currently, no VLANs. I do intend to, but I'm not implementing that until I get routing to Internet sorted.

So I can't ping 8.8.8.8 from anywhere within 192.168.175.0/24. If I tracert 8.8.8.8 it reaches 192.167.175.1 and 192.168.0.1 but thereafter, nothing. I can ping 8.8.8.8 from the shell of opnsense and tracert shows it's not touching 192.168.175.1 as its first hop is 192.168.0.1 so I suspect it's sending from the WAN interface.

Here is a screenie of the routing table, left is opnsense and the right is DD-WRT.

https://i.imgur.com/1BcAMCQ.png

I'd appreciate _anyone_ hitting me with an idea.