Transplant in week 4 is the reason in my opinion. She probably just maxed out the pod and changed the hormones for bloom.
In that moment she got transplanted and recognized that there is more room and reversed to vegetative growth till she felt ready in the new pot.
What
@Newbie87 says is right to. The plant is simply not able to photosynthesize 24/7, she will not use all the light. If you give you're auto's 20/4 or 18/6 they will do just as fine if not better plus you save on the electricity.💪
Happy growing!