It shouldn’t be that way, but every experience and data point I have encountered points that way.
Going from public school in San Jose to public school in Wilmington DE opens one’s eyes.
Japanese Americans don’t behave like east coast blacks.
There are always outliers, but they are numerous sigma outliers…
Your observations are the same as mine. Even people from South America tend to assimilate eventually unless they are cartel/MS13 types.