If you are using coco, it will bind up magnesium so you will need to dose a lot more for it to be fully saturated. Start dosing CalMag at a rate of 1.5x the manufactures recommended dose for the next two waters.
You should start seeing better foliage within two weeks.
Hope this helps.
What I can contribute is:
In the photos, it looks like your coco is dry. Water enough to get a little drainage.
Remember that coco retains moisture, and with this drainage, it also prevents salt buildup.