I had some trouble while back,,similar have taken hundreds of clones with great success ,,,but while back coming from the winter into spring ,,I had issue many were rotting on me so made it simple and has never failed have almost 1005 rate most times,,,if Murphy's law is in effect ,,,,it sounds like the humidity is to high,,was the trouble I was having they were staying to wet,,,,,This is how I solved issue ,,,,,I use Pete moss pellets very easy and cheap and re usable ,,if one does not take,, I soak the Pellet until it is soaked well,,,I then squeeze out all extra so it is moist,,,,,I fill a red beer cup up with dirt,,I make a hole in the dirt for my pellet,,,,I cut my clones and set them in a baby food jar with a little bit of water ,,,That is to avoid air pockets in the plant stem,,,,,I then dip the clone I use a tooth pick to pre poke a hole and stick him in,,,,,Then take the cup and make sure the dirt in the cup is moist ,,,I take another cup and mak a cover for him like a dome but with a few small air vents in side,,the red cups inside is white and gives it a glow for the clone with out to much light,,,,after 5-6 days I put a different red cup over it,,it has more holes,,and a few in the top so it can have a but of direct light but not full ,,day 10-12 remove cups all together,,,,,,Note I do spray the inside of the cup with water but not the plant,,that way it can take what it wants and not wet the soil to much,,they should be flying buy this point ,,here is a few picks of the cup domes I make