My ISP also sent an "all-in-one" device when I hooked up. All I really wanted was to set it up in bridge mode in front of my pfsense box, but couldn't do this.

My ISP also sent an "all-in-one" device when I hooked up. All I really wanted was to set it up in bridge mode in front of my pfsense box, but couldn't do this. I cloned their router's MAC, put their router back in the box and used my existing 'dumb' modem. Perhaps this would work for you as well.