Good evening,
Try upping you're day temperatures too around 28c, the internal temperature of the plant wants too be more around this for autos, they will grow down too 10c but very poorly, stunting growth. Also try warming you're feed water too the temp of you're tent, around 22c, you will vastly notice a difference in the plants absorption and growth with warmer water that's not freezing roots and stunting plant growth!
Happy growing
like
