Accents? Where does my "Asianness" belong?

Throughout the time I lived in Beijing, my mandarin has always been known to have a Taiwanese accent, and I sure thought so myself too. Yet, when I moved back to Taiwan for high school, I’ve had multiple times experiencing people asking me where I come from by the way I speak. I remember the very first time it happened was when I bought something at a shop and just happened to talk to the cashier for a bit. In between our conversation she asked me “you’re not from Taiwan aren’t you?” I paused for a bit and said “well, no I grew up in America and I learned most of my mandarin in China.” And she commented “Oh that explains why.”

That was actually the first time I have had someone ask me that, and this made me wonder myself what “accent” do I actually have? People in China say that I have a Taiwanese accent, and people in Taiwan doubt my mandarin accent. Where does my “Asianness” belong? I guess I would consider myself more Taiwanese since my parents are Taiwanese, yet the time I’ve stayed in China influenced me a lot too. It’s interesting to me how people can just tell that from my accent.