string of hearts in prop box (see description)

First attempt at propagating SOH in prop boxes, trying both perlite and moss.

Currently i do see small offshoot coming out of the nodes, and in a select few little roots coming out.

However some off these offshoots get really wet after some days and they become mushy and they fall from the plant (i believe in the first photo you can see the little leaf separated from the offshoot)

My question is: anybody have suggestions? Lower humidity? Increase air flow?

Thanks for any help and apologies if the photos are not good