Mood decreases rapidly in crimson forests, warped forests, and basalt deltas, causing their "mood" ambient sounds to never play

When moving to a crimson forest, warped forest, or basalt delta, notice that mood never goes up unless you're deep underground and not near lava. Shroomlights and lava seem to decrease mood rapidly, even when the actual light hitting the player is 7 or under. They can even decrease mood through blocks.