Flowering delay

Vege growth persists for 3-4 weeks beyond flip to flower and sometimes longer for the larger plants -- if autoflowers, have to guesstimate start of flower to compare apples to apples... maybe 7-10 days before you noticed first preflowers for a similar comparison of flower phase time frame. Always good to be confident about no light leaks... won't hurt to check. Re-vege would be causing some fucked up leaves, too. single- or limited fingers, no seration (smooth edges). Looks like you may need more sulfur in your fertilizer. That has a distinct pattern of petiole-out chlorosis progression - opposite of tip-in and not interveinal. So, it is easier to diagnose. What do you do? Same thing you do with every plant, pinky. React to what you see, adjust course and carry on. Then, try to take over the world! hopefully it's not some weird genetic mutations with spread out growth and continued elongation of stems - look up "Dr. Grinspoon" strain for an example of such behaviour. I your other plants aren't showing any unusual growth, that also helps eliminate re-vege as a cause. this answer sponsored by "Pinky and the Brain"

do you have a light leak or something to cause it to stay in veg?

Wait. Some plants are slow starters then whoosh, others are steady flowering and some start quickly then go slow. Patience grasshopper!