One thing I’ve learned while living in Thailand and cooking Thai food is that coconut milk is a very delicate ingredient (especially fresh coconut milk).
Whenever you make a recipe that makes use of coconut milk, you need to stir it gently, and keep stirring it in the same directional flow (I’ve explained why better in the video).
If you stir coconut milk too fast and rough it will sort of start to clump or curdle, similar to the way cream or milk does when you boil it. So just remember to treat your coconut milk gently and stir it slowly and steadily without boiling it too hard.