This is what happens when you grow multiple plants and just give them one mix of the same fertilizer to each plant and don't react to what each individual plant is telling you.
Every plant will have its own requirements and you need to feed accordingly.
Just giving every plant the same thing and hoping everything will be ok, does not work.
Pic 1 - multiple plants, multiple issues
Pic 2 - burning from over feeding in general, but otherwise ok
Pic 3 - this plant has at least a nitrogen deficiency and probably wanting extra P and K at this stage
Pic 4 - this plant looks ok
Pic 5 - this plant is hungry for both P and K
Pic 6 - this plant has suffered over feeding but is now starving for both P and K
Symptoms take weeks to get to this level of obviousness, adjusting your feeding to tailor it to each specific plant 2-4 weeks ago would have prevented this level of damage............ask questions sooner rather than leaving it to deteriorate this long if unsure in the future.