I am one of those guys that's puts a sprout into a big pot. It takes preparation and a watering routine to properly do this.
If this fails try my routine.
Fill a 3 of 5 gallon fabric pot with your soil. I recommend a good 20% perlite by volume mixed well with no clumps at all. Water the pot like it has cannabis already growing. Set it in your running tent for minimum 4 days checking water weight on the pot. This will allow you to see if your environmental controls can handle the humidity of a full pot AND to see if you bought a bag of gnants with your dirt. If no gnants appear yaay but if the do you will not have to treat them with a seedling in the pot.
If the pot is clean of bugs go ahead and start a seed. At this point your pot should be very dry and hopefully you filled in the edges where it pulled away. Start your watering routine before you put the seed in. Place a solo cup over the expected placement of your seed and water with 200 ml around the perimeter of the pot like this.
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See the blue solo cup on the plant.
See how each sprout has a dry area around where the sprout was placed. Never water directly on the plant or even near it. Make the plant find the humidity with searching roots.
Water the plant at that rate every 2 days until the plant leafs grow past the perimeter of the solo cup and you would squish leaves. After that you can start raising your water level but now water the whole top of the plant. Prolly around 509 ml. That does not sound like much but it is 1.1 lbs of water and you will feel the weight. Once you get the weight thing on pots down it is so much easier to know the plant needs watered.
Overwater kills more new grows than anything and improper lighting steals more yield than anything.
Ps. When sprouts die that young they can stay in limbo with no growth but still look green. If you get zero growth in 5-7 days move on. It's dead