Leaves turning brown/ black and dying

Hello frinds
My plant is 5 weeks into flowring
Last week many leaves start going brown/black and start to rotten
I removed most of the bad leaves and here’s some photos of my plant
Whats wrong with it ?
I have 3 other plants ( different strain ) and they are health with same feed schedule

Up

temps/humidity/overfed one or a combo

kindnug said:

temps/humidity/overfed one or a combo

Click to expand...

Likely all. It's starting to throw emergency leaves at the top.