I'm a little concerned with the lack of heigh...

It looks like you are really in week 3. I’d expect you to start seeing significant growth within the next week or 2. Nothing to worry about until after week 5 IMO. Even then I’ve had an auto not really kick in until about week 6/7, which eventually turned out to be huge! One of my highest yields. Good luck!

I checked the previous weeks and you have different plants of different age. Most people will take the day the sprout or when they open the first set of serrated leaves as day 1. So they are actually younger than 4 weeks. Anyway, when growing indoors, never be concerned about height, but how developed they are, regarding amount of nodes, and yes they look a bit underdeveloped. Usually that happens first and foremost due low temperatures and / or over watering. Are you sure about the temperatures you posted? where are you measuring them? What about watering? how much are you giving them and how often? Even with the right temperatures and watering, I've seen this happen when putting seeds on too big containers, for some reason they just develop more and more roots and suddenly, when they have an established root system, they take off with a massive burst of growth.