here another grow nearly at the same stage , were i did nothing really different and plant are much more healthier ...

I am still thinking roots.  I noticed the plants that you have issues with or say less healthy are more indica and your sativa grows tend to be healthier.  Indica plants will typically have a bigger root system than sativas.  I know you are regimented and consistant with your prosses, but have you ever considered growing 1-2 plants in same space with bigger pots?

and no i have had indefferently healthy and unhealthy more indica or more sativa phenos.

but, yeah definetely a little rootbound with 1,6gal 6L pots ...