What Happen to them ?

They are beautiful bro and are as they should be as this is a sativa dominant strain. I would ease up on the Nitrogen at this point leave tips are pointing down. From experience iv'e found most sativa dominant strains like less nutrients than indica strains at this stage and it will start stretching like crazy. Good luck

Looks like they needed a stronger light when the where younger or the intensity increased or height decreased. all the same effect. I have a feeling that lights brand is not advertising their true watt consumption. its not uncommon with sketchy brands, tries to scam the user who may not know anything about it. I agree with the below statements about watering, as needed not on a schedule. If its to much, you can stunt growth and give yourself root rot. Good Luck!

Yes, they look weak. They look like they have no enough light and no nutrients at all besides already contained in soil... You could grow them on window sill and just water with plain tap water - and you just might get a better result 😇

A lot of this comes down to genetics. Sometimes no matter what you do the genetics will be bad. In this case I think you’re running into both genetic issues and poor husbandry on your part. If you are indeed watering daily you need to stop NOW. Water as needed, likely in your case every 3-4 days. When you water, about 10-20% should run out the bottom of the pot. This prevents the build up of excess nutrients in your soil. Your light should be run to whatever setting gives you roughly 750-900 PPFD at the top of your plants. You can download a PPFD app to figure this out. Lights on autoflowers should be 18 on and 6 off. Your plant genetics looks to be a very heavy leaning Sativa. Which means your plant will be tall and lanky and there is nothing you can really do about it. I hope this helps.

you dont water soil daily, it has to have wet/dry cycle. if light is really 500w, then only weak genetics and bad watering could make them so lanky and stretched, root system too weak, so plants are weak. soil and coco mix is stupidity in my personal view. by feed you almost have nitrogen toxicity, so its not a lack of food.