Stop “ flushing “ ...... every time you TRY to correct ... you end up with a flush.
Which in all actuality is LEACHING ( the medium ) not anything in plant.
I found roots organic tend to differ ph wise bag to bag ( stopped using it ) and only got rid of my bags as a soil conditioner ( raised beds ) but to me the most “ important “ thing you can do is PH what goes in .
Not what comes out. As long as the ph is ranged to the plant 6.0 - 6.5 then you are good.
IMO .... begin calmag at least 1tsp per gallon with both watering and feeding.
Range ph to 6.3 - 6.5 ( allowing for drift ) and keep it there.
Led grows tend to want less feed as lights don’t allow high transpiration as with more intense hid lighting. I think in the future a better soil choice ( promix / sunshine / FFOF ) can carry your plants better as they are already ammended and prebuffered ( oyster / lime ).