Fondant Shines And Gets Soft In South America

Please help with this problem. My fondant gets shine and soft certain times during the day. If I use a textured design, it snoothes out because of this. I do not know what to do. I heard of a man from Argentina who sold a powder that helps, but I have no other information on him. I am desperate, because fondant is all I use to do my wedding cakes. It is very frustrating. Can you or anyone help me please?