RPM 4-port E1.31->DMX Bridge

I have the RPM 4-port E1.31->DMX bridge and last year I only used 2 universes of data. I'm still likely only using 2 universes, but In testing (after some configuration changes) I noticed that I don't get any data on the 4th socket, no matter what universe I configure it to receive.

My two leading theories:

A cold solder joint somewhere that is for the 4th socket...?

Since the web interface shares the 4th socket, it doesn't get the E1.31 data...and it will work fine if I disable the web interface...?

Suggestions?