It’s on an outdoor plant that was never rained upon or watered from above. I do cover it every night.
Unless it’s just from natural humidity, there’s one circumstance that might have lead to this condition.
One morning , about 3/4 day’s ago, I found slug slime and a few leaves partially eaten. Perhaps the slime left behind on this bud caused the rot. Thankfully, it’s only one bud as far as I can see. I never found the slug.
Any confirmation would be appreciated. Not quite ready for harvest.