Pistils turning brown 4week flower one budsite?

[Benjic93]

Have a roc bud Inc platinum gucci coming into week 4 of flower. Many bud sites on her but this one budsite has pistils turning brown? There 4plants in here with no ball sacs and no other budsites with brown pistils.

Lights on 27c 60%.. lights off 23c 65/70%.

Any idea to slow this down or fix her up? Thankyou