Can you share a description (or better yet, a diagram) of the specific goal you have in mind? Is this a wired or wireless client? What about the the downstream devices (i.e. those connecting to the OpenWrt device (wired or wireless)? Do your downstream devices need to be on the same effective network as the upstream to share resources back and forth, or is it purely for internet access? Does the upstream network need to be protected from the downstream one? etc.
It's really a relatively simple scenario. The router with openwrt installed is wired to the main router running asus merlin firmware. My computer is wired to the openwrt router. The downstream devices, at the moment, are all on the main router, all of which are on the same subnet. The purpose, at the moment, is to gain internet access from the main router for software installs. No protection necessary between devices.
I can move the hotspot if necessary, but then others on the main network will have their internet down, which is not preferable.
As an intent to wrap this up with knowledge, I just discovered the problem. There was a network switch that had been unplugged in the segment where this router was attempting to connect to the main router.