I don't see anything wrong other than dehydration, likely from a lack of roots? If it has hardly any left, it will take some time to re-establish itself into a healthy plant. Likely, a full growing season or even longer. Remember to pot new plants into a pot that's barely bigger than the existenting root mass. Overpotting will lead to roots that stay wet for too long. Also, changing from one kind of medium to another is quite a shock, even for healthy plants. Time and patience will be required if that's the case, or even if not. Maybe others will have more to discuss.