Lost lil seedlings needing direction

Custom blend of coir, perlite, compost, worm castings,humus and manure, etc
Water intial and once every 2-3 days or sooner if soil looks like it’s getting dry, usually water before looking as it darkens soil to make a white tail more visible.
I go about a fingernail deep
I’ve never been a fan of the paper towel or cup of water methods, I have excellent germ rates propogating seeds(90-95% grow and those that don’t are just typically cuz the seeds are no longer viable, had that happen to my pineapple cookies seeds that finally stopped germ after 8 years old) and rather start it straight in soil so it takes hold of what it’s gonna be growing in right away. Seems like germinating about every 40-50 seeds I see something like this happen though so got me wondering why or what may cause that