I'm seeing an odd behavior with light sources.
I have an iksar monk with Celestial Fists and Shackle of Steel. Without either equipped, things are nice and dark. With the Celestial Fists equipped, things lighten up a tad. With Shackle of Steel (only) equipped, things get much brighter. If both Celestial Fists AND Shackle of Steel are equipped, the lesser brightness of the Celestial Fists is in play, not the brighter Shackle of Steel.
Images:
https://imgur.com/a/Bofp55i