Answer: Based on your description it is difficult to make a guess as to what has happened, but I would suspect transplant shock, possibly related to over or underwatering as well. These plants are very shallow rooted and resent being planted too deeply. They need a humusy soil that is evenly moist and yet well drained, meaning it is never soggy or sopping wet but is not allowed to dry out completely, either. Sometimes there is a big difference between the potting mix the plant came in and the soil in the container, so they may dry out at different rates. This can cause problems when watering. Another possible cause would be some sort of physical damage such as a broken stem or an overdose of foliar fertilizer or even something like a dog urinating on it. Maybe this will help you troubleshoot the problem.
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