Needs water?

Cause is excess water the problem is airflow, most likely the back right for whatever reason recieved a little less airflow than the rest, From experience I can tell you those fabric pots are not as breathable as they have you think, depending how water flows through, if water gets trapped with no fresh air to evaporate, moisture very quickly stagnates and time +77 f = bacteria explosion. Only 2 ways water is removed from pots, evaporation or uptake, roots of the plant are still relatively small for the pot size, gravity will pull the water to bottom of the pot where there is no roots or adequate airflow to remove excess moisture. Also make sure to keep an eye on Rh both day and night, if your only taking Rh reading from a lights on perspective, 60-70rg daytime could be spiking higher at night, which doesn't help evaporation.

Overwatered = Limp Leaves + Stiff Leaf Stems Underwatered = Extra Limp Leaves + Limp Leaf Stems likely overwatered it, not all plants will grow the same and some will have stronger root systems, this is why the others look to be fine. Make note of the pots weight before watering and if its good, skipp it till its uses it all up then give more. Another option is adding in more perlite next run so you can't over water the plants. it will all just drain out no matter how much is added in. Good Luck!

Looks like too much water in the roots.