is this bud rot?

Hmm this is clearly the first signs of rot/mold. In picture 1 you can see a black-ish spot in the middle of the stem. Most of the times people get rot on top of the buds and not beneeth thats why not many people know what is going on here. Some people that never find out about this, will see in the havest and drying stage, that there buds are discollord beneeth and taste bad and will blame it on messing up drying the buds. There is nothing much you can do here but just cutt off all infected buts from your plants to affoid more infection. What you can do is a check up on your climate. Do some research on how rot/mold starts when not having the right humidity, airflow, temperature and such :) because by simple removing rots/molds from time to time doesn't fix your problem and do an early harvest is painfull. Goodluck growing :)