One thing to note is that red palm oil should be given in moderation as part of a balanced diet, and not as a primary food source. Too much fat in the diet can lead to obesity and other health problems in African greys. It is recommended to offer no more than 1-2 drops of red palm oil per day, mixed in with your bird's regular food.
Don't worry, it is likely just going through a regular molting cycle. However, it is always a good idea to observe your bird closely to make sure there are no other signs of illness or stress. You should provide your bird with a healthy, balanced diet, regular exercise, and a comfortable and stress-free environment that can help support its overall health and well-being, including during molting cycles