She is a bit young to put into a large fully nuted container. You would be better off running new seed starts in a solo cup with either the fox farm alone or in a milder soil . This way plant acclimates to FF soil on its own and nit swimming in a large volume if it.
Then as it hardens off to soil and grow accelerates , you can transplant that cup as a “ plug “ into that large pot.
That seedling in that large pot has overwatering issues and excessive charged medium to fight thru before its even got its first true leaves. Thats too much for it.