If not for the mannerism, expression , and fashion I can’t even place an educated guess with confidence on East Asians as an East Asian. Let alone ethnicities even more different that I didn’t inherited the depths on. Of course it will be problematic if that person informed their ethnicity and their boundaries yet that information is disregarded and disrespected by the receiver. Ignorant but with a will to learn is always good in my book.
P.S. For a general term you are looking for, I vote East Asian in place outdated “oriental”.
P.P.S. I am not a representative of anyone and my bad take is my own.