When you have babies, you need to trim away all yellowing or browning leaves (or just the parts that are brown or yellow). It's a disease that will spread if you don't, to your other plants too. Wash your hands and use a sterile blade. Sterilisation can be achieved using a solution with bleach.
The survival rate of trimmed clones vs untrimmed clones is significantly (about 50%) higher. Also, spray your babies with some liquid seaweed, or b1.