Nutrient burn or deficiency?

Adding cal mag during veg can be a bit of a challenge. And Calcium is immobile. It does not move up from root to leaves easily. And feeding cal mag while pH is low seldom works. Cal mag should be add early on. My prefer corrective method is to spray with cal mag. It is like an IV feed to human. And way it does not raise pH during vegging. During veg, plants likes a bit more acidic soil anyway. Please look up foliar feeding. On the other hand, I am more careful on spraying during flower. You will likely loose these leaves. I recommend to spray cal mag half strength once a week for two weeks. and extend your plan veg period for a couple of weeks. Please note that my conditions and grow philosophy is different from yours. I grow with organic farmer market nutes. I grow outside in hot and wet climate. My cool and dry season is 32 degree C and 70% humidity. So, most of the stuff won't apply. But spraying cal mag should work fine. For me, I add cal mag when I spray my anti-fungus microbes. You should not need to do anti-fungus spray.

Def water logged roots re pot with chunks of foam or clay pebbles to add pockets of air it wont kill ur root just add like an air layer on the bottom fluffed out its hard to keep soul from conpacting

Looks like they need everything. I feed 1800 to 1900 ppms every 3 days. But im in rockwool. Are u in soil?? I would try a compost tea instead of straight calmg shots. If ur in soil it does some strange shit. I would honest go completely organic if ur gonna do soil otherwise switch to drain and waste rockwool with clay pebbles plz hit me up we can figure this out. Also check out bio ag tm7 on amazon 1/4 tsp a gallon and same blackstrap let sit for 24 hrs then water also add cal mg 1/4strength but not until right before u feed dont let it sit in there......HONESTLY 100 PERCENT ITS ROOT ROT! WATER WAY WAY WAY LESS SO THERES whats wrong and thats how you should feed in soil with non orfanic good luck hit me up withQ??s

You should also not feed cal/mg every feed, once every week or two. Cheers