AsNoriuanswered grow question 3 days ago I would say too low ph. What caused it, could be many reasons. Your soil looks compact, damp and strange. Root juice is for first few weeks, btw its the only right doze by book ( in reality they offer to use it too long ) , bio grow - not enough, calmag in soil is rare needed additive, still doze absolute wrong from manufacturer
( i used it for 2 years with many grows, returned to other brand calmag, had troubles with biobizz ).
Soil needs good saturation on watering day, but at same time needs wet/dry cycle. Lifting pots is only way to know when plants needs water again ...
Tripple check ph and rethink watering habits.
Good luck.
Btw, i see some strange white spots, make sure you have no pests.