I don't think confronting your coworker would help, but I'd go to HR.

I would think anyone in the US could pronounce Mario just from Nintendo in the 90s. I certainly can pronounce Mario and Luigi from that.

I have also experienced people talking about Covid originating from eating habits in China, even though there's no proof of this. This has even happened on this site. There's a lot of misinformation out there.

Several times, I have had people assume I was not born in the US even though I was and have always had an American accent. This happens with White and Black people.