Hmmmm there is a problem with water movement through the plant its not pure deficiency but antagonized lockout or ph drift. The color is not showing a mobility attached to it, which means its more a chlorophyll problem. Its unable to regenerate, indicating nitrogen is no longer available to replenish existing stores as the proteins breakdown from photosynthesis.
The margins edges going yellow suggests the margins are being sacrificed first by the plant so its a semi controlled cannibalism sacrificing "least vital" parts first of the leaf.
Plant is not getting enough water uptake fast enough to keep up with cooling.
Output faster than input.
Oversaturation of the medium is common problem that will cause iron to convert to a form "unavailable for uptake"
If iron goes chlorophyll goes.
Noticed your pots are also sitting flat on the ground, that's a big no no as it creates dead spots of moisture thay can cause anerobic conditions to fester over time.
Its alot harder to get rid of disease than keep it away.
Very tall deep pots too, those tiny little veg plants will barely reach half way through those pots yet, so any top watering will simply sit at the bottom of those pots trapped unless you incorporate some evaporation to assist transpiration until the roots fill those pots.
Noticed you have humidifier, great for vpd daytime. But 100 detrimental at night. If your ambient rh remains over 50-55% at night then almost certainly little evaporation will occur. Wayer is not moving from those pots unless the roots get it or evaporation gets it.
No such thing as too much water, only water that sits too long in the same place.
Keep it flowing. She is breaking down most likely to a creeping lack of oxygen, causing mild ph skew, potential overaturation of pots. All affecting uptake and processing of chlorophyll.
Imbalanced wet dry cycle.