From what little bit I can see, your soil looks pretty damp. Is there any perlite in it? After a good watering, how long does it take to dry out? If it's only a short time, like a day or two, then I agree with Mrs. Hound - you might want to check and see how much fertilizer you used during the last feeding. If it was full-strength (or higher), and you haven't been using it regularly, you'll want to flush it out pretty quick. Those symptoms don't usually just clear up, unless it had something to do with under/overwatering. If you flush, start out with immediately feeding at 1/4 of what the bottle recommends for potted plants, then work your way back up gradually, as part of a scheduled feeding regimen. Those plants can be pretty sensitive to some fertilizers, especially bloom ferts with a crazy high N-P-K.