Ph is most likely your problem get your tester fast.

Yes transplant them and one more thing. If you just cropped them then that will take anywhere from 7-14 days to recover and not really show more growth. So most growers stop the clock for that period in terms of feeding schedule. Like if you veg for 4 weeks and you crop then your total time is more like 4 1/2 weeks to 5 weeks to make up for the loss of time.