I am working on several documents with a specific color, and when I close the AI file, the color switches to a different HEX code.

This issue has no pattern that I can understand, since it does not happen with all documents. It is even more odd because if I choose the color I want with the eyedropper, it remains correct, but if I write the HEX code, it does not. Besides, the color profile doesn't change when this happens, at least that I'm aware of.