After 14 days, my seedling growth looks stopped. ...

Cannabis needs a minimum of 6 hours of DIRECT sunlight on her leaves to grow properly, they will not grow very well at all in indirect sunlight. Stop avoiding direct sunlight and things will improve rapidly, but you might have prevented this auto flower from reaching her full potential, unfortunately, by keeping iher in indirect sunlight for so long already.

I'm with UnkleSkunk - too little light, too much water, and temperatures too low. If you can improve all these things the plant will grow.

How’s it going it sounds like your over watering 500ml every two days is a lot of water for a seedling try letting the soil dry out a bit before you water again and hopefully it will get back to normal in the next few days, hope this helps, goodluck

Not enough light. It needs direct sunlight.

La mancanza di luce è il problema principale, 500ml di acqua per una pianta così piccola sono tanti le radici si devono formare E le temperature sono ancora un po' basse almeno 18 gradi di minima

Id guess the roots are spreading out and when it catches it will grow more leaves and height. Id also be careful to water on a scedule apply as necessary if soil is still wet dont wzter again and i would also consider doming the little lady so she doesnt get too cold

You need more light. Cannabis likes as much direct sun as possible. Can you move it?