I tried cloning with an Aero Cloner/Rockwool/Direct in Soil/Expand Peat Pellet like yours. I was at probably 9/50 successful cloned.
I finally got GH Rapid Rooters with tray, soaked the Rooters in a light Veg base Clonex filled the tray with bottled water (I know people say non PH'd tap is better). Mist with water 2x a day. Kept it right outside my veg lights where it gets about 150 ppfd. Just checked them tonight and 5 are rooted in 7 days. Very happy.
You're just gonna have to keep on researching and trying to find what works for you.
As far as those Expanding Peat Pellets your using I have no idea because when I tried them I couldn't get 1 to root. Good luck.