Using build 3199, I've been trying to get these to generate in a custom playfield and no luck. I noticed that they are also specified in the arid for creative, and in the default survival game they're specified for many biomes of the temperate starter. I cannot find a single one. I've changed the numbers and also tried looking under the ground.
Sounds like they are invisible, which does happen sometimes after an update. I've had reports of players saying that mushrooms are missing on some of my planets too.
I stated that I 'found' invisible Mushrooms on the Snow Starter Planet-Vanilla Game- to @Pantera a few Builds ago.
