Foxtail conundrum…

heat, light, genetics... i've had 2 autoflowers that only did hat sort of growth and all over... the stems never stopped elongating. dr grinspoon type trait? it's a trait that is out there and does crop up here and there. easy to rule out heat and light... while this pic provided looks a little dark, the canopy - growdiaries.com/diaries/162172-grow-journal-by-trichomie78 - sure doesn't look like enough of an overdose of N to cause it... dialing back 10% of N concentration might do you good though. it can't be far off.. leaves aren't too dark and only minor clawing.

The other two I know if are genetic factors and temperature. But it's not your temps because it's usually at around 80 degrees or higher that causes Fox tailing and your diary doesn't say you have temps that high so I'm going with option two. Just the pheno my friend. Hope this helps.

le cime a coda di volpe si dividono in positive e negative x identificare quelle negative normalmennte sono causate da stress da calore o da troppa luce le positive sono dovute ad incroci con genetiche predisposte quindi da una cali me lo aspetterei quindi se non le hai stressate avrai un foxtailing positivo