Red Pistachio-2nd time around

I think your ph of 6.2 is fine, nutrients are readily available to the plants in that range still. EC is to high like other said. and it might be locking out other things. Given the N is in toxcity, it might need an alternate ratio of nutrients as well. I'd aim for a ec of 1.4-1.8 the plants are small and will not be using anything more. I'd check your runoff EC and PH to confirm they are not drastically different then whats going in as well. I'd also get into the habit of when watering, get about 10% runoff each time and dispose of it to prevent buildup in the medium. The golden spots looks like an issue with PH in the root zone. I'd guess you might need a flush and some TLC for a week to correct the issues. FYI calibrate your PH and EC pens as needed. Could be reporting inaccurate numbers. Good Luck!