I don't know what the soil is for the first two....but that looks very like abnormal ph and/or fert problems (like maybe too much ferts for seedlings problems) Also...are you overwatering? That will make them sag as well.....and mess with your ph at the same time.. If the third pic is the one in organic soil.....it STILL seems to have a few issues......but not as much as the other two. Be SURE you are not overwatering and have good drainage. If you are sure that's not the issue I'd try to transplant to better soil......sooner rather than later.