I’m not sure if that’s why they are short but the usual practice is 18/6. Plants grow at night, using the sugar they store from photosynthesis in the day.
The plants aren’t showing signs of deficiency but I would up the nutes dose for a bit, see what happens, hopefully stimulate some growth. What kind of fertilizer are you giving them?
One good thing about the photo sensitive plants is you can wait to start flower until they get the size you want.