Good baking. Consider the following aspects:
1. Is the moisture control before API refining the same as before? You can try adding an appropriate amount of water.
2. Are the crystal forms the same? Because the differences in stirring methods, stirring rates, cooling rates, etc. during crystallization will lead to inconsistent crystal forms.
3. The crystal form is consistent. Check whether the particle size is the same as before? Different particle sizes will also have an impact, which is related to the crystallization rate.
4. Try changing the drying method to blast drying, and do it under the condition of API stability