Nothing wrong with the nutes here toxicity wise
It’s not ph
So with really good leds these days, they cause the plants to go into mag over drive. The plant pulled all the mag from medium and went after the next source, your leaves. But im not sure it’s that bc it would have shown up sooner, if your lights settings have been where they are for a while.
Also when the plants go into flower, and your plant switches gears from veg, a mag deficiency will stop because the plant doesn’t really need that at that point. More cal issues show up in flower.
I think she is hungry for p&k
But also, how long have the lights setting been set this way? Since flip?