You need to kill any mold you see with peroxide, Physan-20 or similar or dilute bleach. Spray down the chamber and cuttings. Don't get a lot of bleach in the soil, it has too much sodium. Change the chamber so it's less humid. You have to transition the leaves slowly or they'll dry out.
Looking at the leaves my guess is that the roots began to form, then died. The soil in the bags looks very wet. If you squeeze that soil as hard as you can you shouldn't be able to squeeze any water out. For the perlite, did you get rid of all the fine dust before using it? That dust will fill up the spaces, trap water and drown your roots.