Great advice above, consider all and act cautiously. Listen close enough and the plants will tell you.
I’m going with this theory: nute lockouts due to pH at the soil/root level.
Whatever the pH of your feed water, the pH delivered to your plants at the root level is way wrong. That’s difficult to detect, but a runoff pH or a slurry test would confirm it.
So, your leaves are starving for nutes that they cannot access and pouring more nutes into the picture just complicates the pH problem without solving it.
Make sense?
Consider the suggestions above and think about which ones will bring your soil pH back into the zone (I shoot for 6.5 in soil), and then try them on an individual pot first. “Listen” carefully for feedback. lol
Best of luck,
-Grouchy