I notice here that generally peoples plants are sexing a little later when started in bigger pots, HBSS for us shows sex from days 15-21 from sprout, so there's a slightly larger margin, that's in 1.5 litre pots which seems to promote faster sexing. I realise you are a way past that.
Also weedman30 recently said he had a deep blue c kick into flower much after everything else, but then it went pretty fast from there so didn't finish up too much later than the others.
Keep an eye on them and keep us posted but I'm sure they'll get into gear for you soon.
CHeers, mitch