The problems seems to me to be root related, perhaps because of wet soil that may have stunted the growth of roots a little in the other two plants and a lot in the tall plant. The dark stem and spacing between nodes, accompanied with what now seems like lockout, tends to indicate over feeding, and the lack of spread of fan leaves to the edge of the pot hints towards under developed roots, roots that are growing straight to the bottom of the pot due to possible incorrect watering techniques. Watering should be thorough, and pots then should be left to complete dry out.
The combination of lots of nutrient and little root systems that have headed to the bottom of the pot (and possibly now spreading along the bottom and heading up the sides), instead of spreading out evenly could cause what we are seeing there, tall plant that is not spreading out as it normally would with normal root development, add in the over nutrient and yeah your plant will get into a little difficulty.
The solution if that were the case, is to let the plant pot completely dry out, feed just water thoroughly watering the entire pot until there is run off, then letting it completely dry out again, tinder dry, as in, so light it feels like there is polystyrene in the pot.
If you felt you needed to buy something to help your plants, look around for a rooting stim like Rhizotonic as an example, and feed that to your plant with each watering until the plants roots bounce back and begin to spread out normally in the pot. The indicator of this is that middle and lower fan leaves will begin to spread out to the edge of the pot, even growing over the sides of the pot.
