Every immigrant I've known that's around my age has told me basically the same story. When they came to the US as a child, and got put into public school, they struggled with reading (they could barely speak English, much less read it), but they excelled at math. I've heard this from people born in China, Taiwan, Mexico, Iraq, Iran, Japan, etc.

Is every immigrant you've known about your age someone you met through work / school and do you work in tech / on a STEM degree? If so then your sample is obviously biased.