OpenWrt modem to asus router (T-Mobile home internet sim)

So I got this modem, https://store.thewirelesshaven.com/products/rj45-usb3-poe-m2-modem-adapter-v8
With the 551. It uses OpenWrt Luci and it provides internet to my asus router. I was wondering or hoping anyone could help me with just having the modem bridged to my asus router and have my asus router handle the firewall and everything else. I already applied IP pass through on Luci but was wondering if there is anything else I should or need to do? Ie OpenWrt firewall and etc. I’m kind of a Noob to all this but researching and learning as I go.

What is installed on your modem (I believe Quectel RM551) is not the official version of OpenWrt, so you need to look elsewhere for help.

Does this help? Other than that it has QuecManager

It appears you are using firmware that is not from the official OpenWrt project.

When using forks/offshoots/vendor-specific builds that are "based on OpenWrt", there may be many differences compared to the official versions (hosted by OpenWrt.org). Some of these customizations may fundamentally change the way that OpenWrt works. You might need help from people with specific/specialized knowledge about the firmware you are using, so it is possible that advice you get here may not be useful.

You may find that the best options are:

  1. Install an official version of OpenWrt, if your device is supported (see https://firmware-selector.openwrt.org).
  2. Ask for help from the maintainer(s) or user community of the specific firmware that you are using.
  3. Provide the source code for the firmware so that users on this forum can understand how your firmware works (OpenWrt forum users are volunteers, so somebody might look at the code if they have time and are interested in your issue).

If you believe that this specific issue is common to generic/official OpenWrt and/or the maintainers of your build have indicated as such, please feel free to clarify.