I'm pretty new to this, but Gaia 4-4-4 is one of the variables of my current grow. It slowed down quite a lot, and leaf problems once I transferred the plant to coco+perlite+gaia444+RAW microbes. I've had another problem similar to yours back in April, but I can't remember if I was using Gaia 4-4-4 for that one.
This is my current seedling. It's 10 days old and it's an auto. Notice the little "spines" on the tips and some yellowing! Not sure what happened there. Might have been the Gaia, genetics or the fact those "spines" kind stuck to themselves for a couple of days. Very weird. I makes me thing Gaia is a bit hot, or maybe I should just use it without any microbes to help break it down. I got some burns and necrotic tissue on another plant I added Gaia + Microbes very recently. But might have been just overwatering, although that plant didn't respond that way with same volume of water before the amendment.
I have moved it into this final pot now, made a hole with just coco/perlite so it doesn't touch the amended soil and EWC on top. I'm also germinating another seed and will just do coco. Should have answers in the next couple of days.
You could try starting some of them free of nutrients next time as insurance. And please let me know what happens! Cheers.
The other plant in case you're curious like me.