XB7 no longer functions in bridge mode after Comcast maintenance. HELP !

About 3 weeks ago, I put together a nice little silent PC with dual 10 Gbps NICs , installed Opnsense on it, and set my XB7 gateway to bridge mode

Everything worked fine, until Comcast did some maintenance yesterday on its network all day long. At the end of the day, when I got home, I was getting random disconnects or failure to connect in the first place on about 90% of web sites, from a wired system. Comcast, true to form, blamed my router. If I switch the XB7 to router mode (bridge mode off), I don't see the connectivity problems with web sites. I still have my router in the picture. So this is doing double-NAT, unfortunately. And of course, the VPN I setup on my Opnsense box cannot work that way. I need bridge mode to work again.

Using the Comcast built-in router isn't an option with the nearly 200 hosts I have, and growing.