That’s exactly what it is, if his is getting less light in a day the plant was triggered sooner thinking the season was closer to fall. A shaded spot at the beginning or end of the day is all it takes.
Def nothing to be disappointed about, means u got 2 more weeks of veg getting nice and bigger before it flipped, in theory u will have the better yield and possibly a lil better quality since your plant is getting more overall light