My guess is lockout of sorts and a little too much water. Sometimes giving it a chance to recover, and dry out... then go back to keeping it moist, but never wet. Watering from below is ideal. The roots need to be able to work and need oxygen as well as water. Leaving a bucket of tap water sitting overnight will dissipate the chlorine, too. That's easier on the microbe community if your nutes include them.
They sell a wonder fix here, I see... called LIFTA.... might wanna search for that topic. Seems to work for most everybody.
They look great, maybe just a little over loved.... ??? it's hard not to. They'll come out of it soon. Some strains are nute sensitive, too. Some like heavy feeding, and some hate it. Genetics will make that call.
Back to smoking my bowl.... I hope I don't read this in the morning and ask myself,,, "why"?