First photo grow - Slow in the 3rd week of flower

Hi

I've grown autos before and they were fine.
Thought Id try a regular and was wondering about the switch from 18/6 to 12/12.
A criminal+ which says, 2 week veg period and 55 day flower so 10 weeks.
After 2 weeks I switched out my 4x 23w CFLs from veg to flowering spectrum, and switched to 12/12.
After a further 3 weeks, growth has been fine but she isn't even showing signs of sex really.
I get the switch is stressful for the plant, but is this too slow, is something wrong?

Someone suggested leaving it in the dark for 24 hrs? I see this as a good idea. worried it will stress it tho.

Any comments welcomed
Many Thanks

under normal circumstances a regular marijuana plant isn't sexually mature until 12 weeks so that may be your problem, i've never run autos nor have i ever run regulars and flipped them this soon.

i prefer regular genetics to autos because autos are a one and done kind of thing and me, i want to be able to reproduce my results into the future, i have a half-dozen keepers that i have been cloning and flowering for years now and you just can't do that with an auto.

bozo