I too would avoid humidity domes and comparable measures. Often it seems plants are being overly babied or arcane measures are employed in hope of higher success. I dont think it is the humidity itself that kills the plant, but humidity may cause issues like certain pests, fungi and so on. But mostly i would attribute this to environmental change. When a plant is settled in avoid changing its situation as it causes stress, especially changing back from humid to normal. So in essence humidity chambers are not wprth it other than in cases where it is the only possible way.
They strike in soil that is kept moist fairly well. And water glasses of course.
I tried air layering on theese with little success. It certainly looked like it is going to eventually work but the root growth was so slow that it would have been a PITA to attend to it during all the time.
I'd go from simple to elaborate, if it doesnt strike in damp soil, try a glass of water, if it wont work, try a humidity dome, if that doesnt work try air layering and after that micropropagation.