This is weird..whats up with this stem?

I noticed this a couple of days ago forming and then today the leaves on the buds between the weirdness on the stem and the main stem are turning black and yellow.

What is this??

what is your humidity in the grow room like? Could be mold or bud rot. I would take that branch off either way to prevent it from spreading further

The humidity is 40-50% and temp is 75-80F. This is the only bud and stem like that. Thats the weird part to me it being so isolated. But hell yeah im cutting that shit off.