Thanks Jimmy, I will try to modify.
I think I did not make my first question clear. Let me explain again.
I have a product with two option choices.
eg., Frist option: Size
Second option: Colour
When I try to edit the second option choices Red, the screen jump back to the first option Size, but when I try to edit the first Size option, it can be edited. This problem only happened on one particular product.
Could you tell me what went wrong here?