Your plants have only been in flower for 3 weeks and they've got a long way to go yet! The buds have a LOT of fattening up to do, believe it or not!! Looking at your diary, you're only giving them Flora Micro when they should be getting Flora Bloom and Flora Grow as well... they're starving for more nutrients! Look at the feeding chart for your nutes and see how you should adjust them... Since you're growing autoflowers, I would suggest following the Light or Medium feed chart - not the aggressive feed chart ... here's a link to them: https://generalhydroponics.com/wp-content/uploads/FloraSeries-Custom-Feed-Charts-1.pdf
Keep going, give them more nutrients and good luck!