I think you may have a pathogen in your garden. I had some issues a while back and found it was a pathogen in my soil. I think you should take your ez-cloner and wash it out thoroughly with alcohol or H2O2, and wash down everything that touches this setup. Then get it in its place
(or move it to a new location that is isolated, where you can keep a couple low-level, soft white CFL bulbs over it(not right on them, but about 1 foot away). Mix up your clonex solution in it and add some of the rooting powder to the solution rather than trying to put it on the cuttings. When you set up your water/cloning solution, make sure the water is exactly 80f (get a meat thermometer to stick through one of the neopreene pucks to keep an eye on the water). (by the way, make sure those neoprene pucks are washed well with the peroxide as well before using them).
When I take my cuttings, I try to get them about 6-8inches long and stick them into water right when I cut them, then move all of them to the cloner for final cutting and setting. I trim off the leaves until I have just the top growth and 1-2 leaves. If the leaves left on the cuttings are a little big then I cut the tips off about 1/3(don't know exactly why it helps but it always does). I then cut off another section of the stem so that I have about 1-2cm of stem just below a leaf node that the leaf was removed from. I use my scalpel to slice the stem on a long angle on either side so that it goes to a point, then stick it in the cloner.
After doing that, turn them on and try to maintain the air space at 78-80f with only a very slight breeze
and don't put the dome on it. I have found that the dome can cause them to hold too much moisture. Try to leave them as undisturbed as possible and make sure the sprayers are working good before starting everything. You can still spritz them once a day but try to maintain the temps in the water and air and I bet you will have roots inside of 10 days. Root grow mojo Bro