if you're doing this. you're doing to much IMO
i saw your clone question earlier, but i've never used an ez cloner, so can't say much there.
but IMO cloning should basically be cut and forget.. no messing around with underwater cuts, watering, or even misting..
my EZ cloner; peat pucks under a store-bought cake dome (i liked the height of this over typical domes)
i do the cut at 45 degree, and trim back fan leaves. but after they're in the puck, under the dome. nothing till roots. they sit under my t5's in the veg area to keep enough warmth and light.
simplicity is best i've always found with cloning.
what are they under for light could it be too strong? high temps?
have you changed anything as you said in your other post you had success untill recently (maybe summer, and to hot? or winter and too cold?)