Auto pre flower limbo

You may have a photoperiod.. bit too early to be certain. This happens occasionally.. whether it's mis-packaged or pollen contamination while breeding, or a breeder simply not good known steps to create ~100% autoflower seeds. I can't tell in these pictures if you have pistils at terminal buds or not? If you only have "1" calyx per branch (at base), those are preflowers and can show up in vege phase. Pistils seen at terminal buds are not preflowers and that would mean it is in flower. -- little tufts of white hairs forming at top of any branch... So, if you think it's not in flower, i'd wait another week to be certain, and if nothing changes, that plant is going to require a 12/12 light cycle. This is fine if you can amp up the light to maintain the same DLI you provided over 18 hours. If you can do that, the yield will not suffer due to fewer hours of light... it is not about the number of hours but the number of photons per day. More intense light in fewer hours will provide the same DLI. It's inversely proportional to the change in hours of operation, so 18h to 12h would require 150% more photons per hour to maintain DLI. If you do go that route, do not switch back and forth from 12 hours schedule.. it needs to remain on 12hours of uninterupted darkness until the end. Autoflowers are not affected by light schedule in regard to transiationing from vegetative phase to flower phase. They do not have the same feedback loop (hormonal response). Nothing is being produced in darkness that will cause the flip. If you do see pistils forming at terminal buds, just be patient.. it's fine. Not all autoflowers are on the same schedule. You could have one that just has a slightly longer vege phase than the others.

The rest of them seem to have gotten the signals, hmmmm she does look like she started the hormonal flip, just very behind. If they are different strains, one could just very well be a longer flowering strain, there are a lot of things you can do to promote florigen, but it's most likely just a strain thing. Temporarily drop the light cycle from 12/12 to 11 hours of light and 13 hours of dark for a few days to trigger a stronger flowering response. If they are completely different strains, a staggered flowering schedule is highly expected. She is already showing early signs of that hormonal flip her body has recognized the internal clock, she is just taking her sweet time. If you want to give her a nudge to boost florigen production and help her catch up,. Or try taper down the nitrogen N and ramp up the phosphorus P and potassium K. Excess nitrogen can sometimes keep a plant stuck in a vege signal loop. Add more red and far-red wavelengths (around 660nm to 730nm), (but evenly) additional 730nm witohout same amount of extra 660nm can induce stretching.