It’s not a bias against immigrants, it’s a bias against the unknown.

I’ve had an identical experience as an 19 year old college dropout trying to rent an apartment and buy a car with no established credit history. It at least 5 years to qualify for my first unsecured card with $1,000 credit on a 6-figure salary. I could not qualify for any vehicle, not even a used cheap Honda Civic with my lack of history, and I had to play the Craigslist rental game for years as well.

There's a small difference... at 19, you truly didn't have a credit history. A middle-aged immigrant from Canada likely has a credit history, but for some reason, it's not portable across arbitrary boundaries. Canada-US is a pretty solid example... We're neighbors, we both have stable economies, modern banking, etc. From a consumer's perspective, there's no good reason a credit history shouldn't carry across that border.