I'm going to go with switch to bloom nutes NOW.
You are showing N toxicity even at that outrageously low EC. That seems very odd. Have you used any superthrive or thrivealive in the past couple weeks? What is the medium that the plants are physically planted in?
And the temperatures you noted- is that in the canopy or just at some location in the room?
Your res temp seems okay. What are you using to AERATE the reservoir?
Those look like tropical sativas. What is their origin?