I believe 100% this is the problem. Others have mentioned they do not need much water or food at this age. They have all they need in the coty’s. Babies get all the moisture they need from the air which is why we need to keep the humidity as close to 80% as we can. Temps need to stay right around 80ºF as well for the first 2 weeks. If you moisten the solo or small starter pot and keep em in a dome at the targets mentioned, you will not need to give them any water. When she is tapping, she isn’t drinking from the soil.
Here is a link to a germinating thread and I did a step by step process through 3 weeks with pics. Hope it helps, Less is more at this stage. I saw someone say hands off…this is true. The first 2 weeks, I do nothing but give her the enviro she needs to start her journey.
All targets I can think of
Light - 250-300 ppfd or 15-20 DLI
Heat - 80ºF
RH - 80%
Watering - None to very little
Food - None for 4 weeks or so if in cannabis friendly soil
I just looked up the soil. Ingredients are very similar to Ocean Forest which is on the hot side for seedlings. Did you do a slurry test? Do you know what the starting PPM’s and pH were outta the bag?