That's timing mate. When they were fattening they didn't receive enough light
Was it mostly larfy/airy bud..
Thing with outdoors. For you to be hitting that high lux you need to be flipping in mid June, and need the 3-4 weeks of fattening as high of lux as you can get. If you are growing outdoors make it so you have your plants in pots and can trigger the flip in time for the killer sun.
Good Growing