Initially treated as calmag def, but unsure now, think possibly light stress ?? Don't know... other ladies seem to be going along okay, only fat banana showing any real cause for concern.
Any advice on next steps, apprechiated
Generally under fed with a developing calcium deficiency.
Never grow at 24/0........18/6 is optimal.........ALL plants NEED "sleep"!
Each and every plant will have its own requirements.....feeding multiple strains the exact same ferts does not always work.
It is a late stage Nitrogen and potassium defiency, you should be feeding 4ml per litre of Bio Grow, 3ml per litre Bio Bloom and 2ml per litre of Top Max at this stage according to the BioBizz feed chart.
I have used BioBizz for 6 years.