Pistils in week number 3/4? It's an auto, I recommend 20 hours of light and 4 of darkness.
Given the growth it has, it also makes a lot of sense that it's automatic, I definitely lean towards that.
You say you saw on the seed bank's website that it's photoperiod, did you check that there isn't the same genetic name in their autoflowering section? Some banks have genetics with the same name in photoperiod seeds and autoflowering seeds, which can be a bit confusing the first few times.
Cheers