That brown nug looks like botritis aka Grey mold or bud rot ... You might wanna keep a good eye on your plants... Can spread easily... Try to avoid touching it and touching plants again... Get it out as smooth as your can....im working in a cannabis cultivation facility and we had a botrytis brake out snd it looks similar to the photo...if you open the bud and it looks like spider webs or cotton... It is botritis but ifbits only the leaves that's turning brown i can't tell what it is..
like