The plant is N toxic, that is what causes the tips of leaves to curl under. Do you have a means to check your EC/PPMS and PH? It's the only real way to tell what is going on in the root zone and what your nutrient levels are.
Hi everyone I have two blueberry autos going both in biobizz light mix in 7.5l pots, one is very happy and another isn’t the leaves at the top are droopy and some fan leave are curling downwards, i water both every 3/4 days till I get run off and let them dry out a bit for watering again, they both get biobizz nutes, I’m giving them 1.0ml grow per litre, 1.0ml bloom and 0.5ml top max, both at over 6 weeks, I just can’t work out why this ones doing this with the leave curling and it is behind the other by far, any help would be appreciated, the last photo is my happy one btw