New Grower, Plant Stopped growing

I have a plant (Nirvana Sky Auto from Flash Seeds) that I have been germinating as seedling in Rapid Rooter since 6/18. The plant was progressing well and I was wanting to pot up on it after lifting the Rooter twice over a period before 6/30 and noticing lots of long roots existing.

So on 6/30 I potted up to 2 gal Smart Pot in Light Warrior with a little dry Mycos in hole. Now the plants growth seems to have stopped and the leaves at the bottom are still progressing towards looking further burnt and yellow. The leaves above are green.

I've been giving pH 6.2-6.7 throughout.
24 lights Mars Reflector 144 x2 on Veg.

I have all the Blue Labs tools ( pH, soil pH, TDC/EC) .

Could anyone be of help to me in this situation?
(Also you can't see it but on one of leaves where its burnt it also looks to be purpling.)

Autos are known to not like transplants, but the few I've grown didn't have an issue with it. Pics would be better with normal lighting so color can be seen, just looks greenish blue. Doesn't look very happy so I'd guess transplant blues or maybe too much nutes, but again hard to say with the color of those photos. Better luck on your others, autos don't recover all that well so who knows if she will produce.

I'll try to get some pics with normal lighting, but ya I think I was a little too anxious to pot up on my first time.

Again its just the bottom leaves and not the upper sets that are failing. The conditions were there before transplant and only got worse and stopped growing after transplant.

Is there some indication in the plants growth either (leaves, height, or time) that you wait for before transplanting?

May have fucked up with executing with the propagating dome. I probably should have soaked, paper towel method, then Rapid Rooter in propagating dome for 4 weeks dome-on & only cracking vent a little as needed and not do shit except straight water.

Here's a pic of the plant early this morning.

You can notice the yellowing and purpling.

Now, just watered and took pH and PPM readings.

The pH sample taken from the pan of the just watered plant was 6.7 6.6. ( I adjusted the water to this reading prior to watering plant)

The PPM pen read 0.4 consistently on many samples.

Is there anything wrong these readings? Should my PPM be different? I'm not using any nutrients at all right now.
I believe from time last night to time tonight that the plant is going to be alright and that I believe I've noticed new growth in the plant since this time which is encouraging and changes where I thought the plant was heading.

But to ask again anything wrong with those sample readings in the soil and pH'ed water that I'm given them. The tent does read 90F right now and about RH of 43%. Is it heat stress?