4th week of flower, bud node turning brown?? Please help!

Hey I actually posted here recently about my plants yellowing too much during flower but this is an unrelated issue. Recently the leaves have been drooping and I haven't been overwatering. I usually water every few days based on a moisture meter. Today I went outside and found that at the top of my one of the branches, the bud and leaves were turning brown. The plants genetics are supposed to turn the plant purple around this time but instead this spot is turning brown and smelling a little funny. Any ideas why? Also the plant is extremely yellow even though I've been feeding it Biobizz grow and bloom (1teaspoon/gal of each)

I have that same problem with parts of the top bud turning brown and YES, the smell is different.

Hopefully someone has an idea why...

Mold. That is straight up mold. Cut out all the bad shit. Then clean the wound with 1 part hydrogen peroxide (3%) with 1 part water and a cotton swab.

Get rid of the humidity in your veg area with some extra ventilation and try to get light on the infected areas. Hopefully it wont spread. You also will need to sterilize your grow area to kill any spore that may be lingering around.

I can see some good signs there. One of the growing process.
______________
papaver pods ( planter )

I'll put in another vote for bud mold. Listen to greensister.