Chain 2 routers *with* OpenVPN on one

Interesting setup here, I can't find anyone who's doing the exact same thing.

My reasons are numerous, but this is how I've figured out that my setup has to be to get the config I need.

Router 1 (WNDR3400) - DD-WRT
Router 2 (Netgear R7000) - kongac build 25090

Computer -> Router 1 [wireless disabled, DHCP enabled]
[THEN]
Router 1 -> Router 2 [LAN-to-LAN, wireless enabled, DHCP disabled]

Internet, router access etc. works fine in the chain so far, seems perfect. However, I am trying to run OpenVPN (PIA) within Router 2. I have done this many times with success, and I am sure the router is configured correctly for VPN.

The catch is that... previously running ONLY Router 2, the VPN setup worked fine. When I daisy chain the routers and use Router 2 only for wireless access, DHCP off... the VPN does not activate. It's like it totally ignores that code I put in the startup commands. I want everything on Router 2 to be automatically behind the VPN.

Is this issue router-specific? Any explanation for why it would ignore the VPN code just because the DHCP is disabled?