Looks like bud rot to me, I would chop the entire plant and give it a wash with some peroxide to help kill of any remaining spores, cut out all dead rotton stuff and start the dry and cure right away.
On you next grow will need to watch out for the high humidity and keep the air flow up.
Good Luck!
***disclaimer, multiple people are answering all questions as there is a contest called GOTM, when a user is selected as the answer they get a point. Please see the contest page for information regarding the details:
growdiaries.com/giveaways/GotM-August-2022
Please note, when you reply to anything on the questions part of Growdiaries website, no one will be notified of this. Not even if you use a "@" tag in their name. Best to reach out to them in DM using your inbox, it can be found in the bottom right hand corner of the site. It's the small paper airplane button, it will be highlighted green if you have new messages***