That's very interesting to hear. I wonder if it is something specific to that corporation, or perhaps your role at the corporation, though? All the Chinese-born people I know would be pretty surprised if any non-Chinese person could read Chinese.
My experience is that attitudes are often quite different if you look like a Chinese person.
So after about the 5th time like that, we had the argument. It turns out that she was just being scared and telling me to be careful, not knowing how an English speaker would take that contextually.