QuincyKat

Wipe the stem gently down with a paper towel that has a anti fungal soaked in a bit, and if you have earthwoorm castings do the same thing with an earth worm casting tea to replace some good bacteria and crowd out the bad fungi

Sorry i forgot to get back to you quicker, that is forsure some sort of fungi, almost looks like botrytis but that normally only happens in the buds, i would go get a anti fungal, serenade brand has a good one that is nice, safer is a good brand too

Ive never had this problem so i hope it helps you out