Hey there, Trickster.
I would say you have a nice set up going. And I think you will have success shortly, it may just be taking a little bit to get started. Just remember that as long as the leaves are mostly healthy, then the cycle is still going and roots
will happen.
For me, I have done well over a hundred clones of 3 or 4 different types of plants over the last year and so far I have only had 5 die on me. And now that I know what to NOT do for those situations (mostly laziness) I think I can prevent those 5% from dying too. There are a LOT of intricate things I do, such as: I do all of my final cutting under water to eliminate the possibility of a bubble in the stem, I use rock wool cubes in a humidity done that I control the temp and humidity to be what it needs to be at the current stage, I use a tooth pick to close the rockwool over the stem so no air gets in, I put gel on a tooth pick and use that to make the pilot hole and then dip the cutting in the gel to get a lot of it in there, I push the stems lower than I have before and get more root starts to grow, I use an inclining system of
very light nutrients, and I prune each cutting accordingly to have just the right amount of green leaf as needed.
Those were just tips that I have grown to incorporate. I also have started using
GH Rapid Rooter and so far am at 100% success. Every plant has lots of roots and new green growth is happening on all plants (for this round: 18 plants total).
Oh, I almost forgot... I keep my ph between 5.6 - 5.9 and have never had a problem with getting roots to start. --- I lost 3 plants in my life time to mold/fungis, which I have modified my air flow exposure to help and have a bottle of hydrogen peroxide at the ready to mix lightly with water in a spray bottle. I have also found that turning the plants regularly helps prevent mold/fungis, every added measure helps and it's good for the plants to get light exposure to all sides.
This round I also started using my pruning techniques which I usually reserve for when they go into the DWC or soil. I cut all big leaves off except the top one and as SOON as I see the new "branches" start growing true leaves, I prune that top "original" leaf leaving all of the plants root system to power each new branch.
Sorry that this doesn't perfectly relate to your aeroponic setup, but sometimes tips from one method could be used as an idea to help tweak other methods.