FIXED IT, but there's a GUI glitch.
I swapped the WAN and LAN (BR-LAN) ports around.
First, I opened the Advanced Settings GUI, and selected Network/Interfaces.
Second, on the Interfaces Tab, I selected ‘edit’ on the WAN Interface and changed the Device from eth0 to eth1 and saved (NOT 'Save and Apply').
Third, I then selected the Devices Tab. On the Devices Tab, I selected ‘configure’ on the br-lan device. Then I selected the Bridge Ports dropdown where I unchecked eth1 and checkmarked eth0 and saved.
Finally, I selected Save & Apply, and physically swapped the Ethernet cables around.
After rebooting, the Brume 2 connects to the WAN on eth1 and gets an IP address just fine now.
BUT, the GUI page is incomplete since it doesn't show anything about the WAN connection or IP at all. It just shows WAN Port Status: using as LAN port. The only way I can see the WAN connection/IP information is on the advanced GUI page.