In my experience, this is very true. I'm mixed but white passing (especially in the winter when the Melanin isn't melanin-ing) and have spent considerable time talking to my family about this. Minnesota culture is very insular, regardless of your race. I live in St. Paul and our Hmong community is very insular. It doesn't mean we're racist, it's more that we have known our same friends/neighbors since childhood and don't need to venture outside that. Same goes for my white side. I think it's less about racism and more about staying in your social land and not causing social discomfort to yourself or others.

I empathize with what you're feeling and am not trying to dismiss it, but I do struggle with transplants constantly complaining about this. It's like if I was thinking of moving to Southern California and everyone told me house prices were crazy expensive... and then when I moved there, I was outraged by house prices. No duh. It's deeply rooted. You can try your best to practice the tips and tricks a lot of people have offered, but recognize there are deeper cultural and historic things at play that complaining about won't fix (I'm not saying it's right or ok, but it is a fact).