I have three ISPs (cable, DSL, cell), each run into one of WAN, WAN/LAN1, WAN/LAN2.  All connections seem to be working, and to a degree traffic is flowing.  (Just rebooted, so traffic is low.)  However, I am unable to configure load balancing for WAN ports other than WAN, and unable to set online detection.  I've searched through the forums (and Google at large), and can't seem to find anything related to my problem.

Basic network configuration:

However, I appear to be unable to "detect" WAN/LAN1 and WAN/LAN2 as WAN ports:

1.  When attempting to enable bandwidth-based routing, only WAN shows up.

2. When setting "Online detection", only WAN shows up:

Just in case it's at all related to this, I do have a set of vlans set up on ports 4 and 5 (the non-WAN ports) to provide some routing options.

Thanks in advance for any pointers!