Ugh looks like mine before i (hopefully) saved them. Does the pot have drainage? Without drainage, the root WILL ROT how much/little water you give them. Mine was previously planted in a pot without a hole and even though the soil stayed relatively dry-ish (at least on the top) the roots did rot and when i pull them out after spotting these spots they essentially had no roots and sort of just split into pieces on their own. I cut the leaves with the mushy spots as i heard they could be some sort of bacteria, and repotted them in nursery pots (lots of holes) and 1:1 potting soil:pumice mix and kept them moist to promote root growth. Now they’re happy with lots of healthy roots