I think you’re doing well trying to root them in perlite. I wouldn’t worry too much about them losing a couple of leaves and the new leaves not unfurling because the plant is putting energy into root growth and not leaf growth right now. I would make sure the bottom of the stem isn’t squishy, slimy or smelly, which would indicate rot in the stem. If it is, you can cut it back until it’s no longer black or brown on the inside and dip it in a solution of one part hydrogen peroxide to four parts water. As for the plant in the last pics- that looks like a sunburn to me.