This is a desert rose. I have lots of experience with plants, but this one confuses me! It likes to drops leaves. It dropped all leaves except for maybe 4 this winter. I figured it was too cold, so I moved it farther away from the chilly window. I think it’s maybe a watering issue? I let it go completely dry before watering again. I don’t think it’s a light issue. It’s has always gotten at least 6 hours of direct light -whether from the sun or a grow light. Now it looks good after regrowing leaves from the winter drop. But I recently watered it and it dropped 8 more leaves! The leaves turn completely yellow and dry before dropping. Are these just really fussy plants or am I missing something?