Looks like P defc. to me as well, but the why is the question,... most likely it's a simple lack of, knowing MC and that dosage level, but your in-pot pH must be checked to see if that's off... Too acidic and P locks out,....
...do check pH going in? What's you water like for pH and ppm?....extra Ca-Mg isn't necessary all the time, and party depends on the water hardness,... hard water + too much Ca-Mg can indeed start to cause problems with uptake of other nutes if it builds up cumulatively,...
You'll need a decent pH probe made for in-pot measurements; run-off is bollocks for accurate pH,... a crude estimation can be had using RO/Di water, with a pint or so of run-off and sample collected at the end, not at the beginning.... the Accurate 8 is fine, or the equivalent, it's under a few brands now, same unit, different name and pricing.... just don't bother with the cheapo skinny probe or combo meters, next to useless!
I'd take her off 24/0, trust me, it's not worth it unless you have everything else DIALED in,.. more is not better even with light, they can utilize only so much per day,.... 20/4 or 18/6 is fine,....