I have these wierd looking tips coming from the crowns on the bud sites. It could well be a light leak problem so its getting a small amount of light when it's meant to be off. Will check. All I know is their tops had started to flower and you can see particularly in week 11-12
Took me a while to see what your on about. Its right at the top of the plants looking like the lower part is in bloom but your getting new looking growth right at the top. That's a strange one. Is it in complete darkness for 12hrs no light leaks or anything in there that has a small led that's on when it's lights off.