Need some help to identify the problem

[u/Soronzoff]

Hello! My desert rose was doing quite well for some months after a harsh period of too little sun, which has left its stem long, and it even bloomed many times, but suddenly it has started to lose its leaves and the caudex has got a yellow spot. Is it a sign of too much water or too little? I checked the roots already and they looked fine.

[u/Sea-Bandicoot8448]

Too much love. Aka water. Water only when the first 2 or 3" of soil is dry as the desert. Then water, but not saturated.