The new growth looks like it was a little burnt from being too close to lights??? maybe its just a bad pic and I am seeing it wrong. As far as the other lower leaves, my cuttings do the same thing when they are too bushy. I trim all the larger fan leaves so the cutting can concentrate on rooting rather than growing. I usually try and take cuttings with only a couple sets of leaves, otherwise my lower leaves die off just like yours. I would clip the lower leaves if they are dead and keep doing whatever youre doing. I have had this happen to me many times if I dont trim the big fan leaves in half and remove excess growth. All I do is trim the dead leaves off, and trim the other fan leaves in half. I usually dont touch the new growth, just leave it as is. As for your new growth, if it is actually black and dead, I might remove that before it starts to rot. Otherwise you are inviting a whole bunch of other problems
