I believe that buying these over the market stalls changes their internal data. I bought one and have been unable to apply it armor or weapons. Gandora just bought two sets and was also unable to apply them. Please try to fix this. I will proceed to notify others so that stall owners don’t sell them.
It seems to be similar to the bug that changed the data of dragons which makes me wonder what other items have this characteristic. This might also lead to exploits of ‘enhancing’/ changing items by putting it in stalls and selling it to onself.