Drooping yellowing and rolling leaves ph lockout?

[Cornercab36]

Hey guys I'm about 5 weeks in from seed under 8 15 watt led bulbs
Growing in a mix of happy frog and ffof I had experienced slight nutrient burn in week 2 but they had completely grown out of it for a few weeks so I'm reluctant to say its nutrient burn
The leaves are drooping heavily accompanied by purple/red petioles
One of the plants shows yellowing and browning while the others leaves are drooping and rolling so to say
I tested my soil ph at 5.4 would this be caused by low ph lockout?
Room temps stay between 70f and 82f
I removed one from its pot to take a look at the roots they look great completely white no signs of browning and not "overly crowded" to suggest being root bound

 

[Blitz35]

It's not a cactus...they do need water!

 

[Cornercab36]

It's not a cactus...they do need water!

After a decent watering they seem exactly the same if it were under watering wouldn't they have perked up within a few hours? The leaf roll does appear to have gotten slightly worse. Sorry complete nube here could I have turned an under watering issue into over watering? I watered about 2 cups until only a few drops run off water at 7.0 ph from the tap

 

[Budzbuddha]

FFOF / HF ..... ph at 6.3 - 6.5 ..... no more ..... no less.

The “ important “ part is what’s going in ( ph ) than what’s coming out.