Asian auditions

I went into an audition not too long ago where I was supposed to be playing a Korean kid. The breakdown said I needed to know conversational Korean. Me being Chinese without even knowing any Chinese language conversationally, I asked my manager if it was a good idea if I should go. He told me I should just learn a couple of phrases and just go in. I got my friend to translate three phrases that fit into the script and I made my best attempt at emulating the accent and such. 

I went to the audition and signed in and sat across from another Asian guy. As I was sitting there going over my "Korean" lines I noticed the guy across from me was also doing it, but out loud. Eventually he asked me "hey, so do you actually know Korean?" And I told no, I just got a friend to translate it for me. He then tells me he basically did the same thing and that even though he's Korean he didn't really know the language.

I go in the audition and do pretty ok at it. Afterward he asks me if I'm actually Korean and I say I'm ethnically Chinese, but I have Korean friends and have picked up a few phrases here and there. Overall I got the sense that he wasn't super convinced though. As I leave I take one look at the sign in sheet and realize that most of the people called in aren't teallynkorean so they probably all faked it.

I've gotten a few auditions now asking to either speak mandarin or have a native Vietnamese accent and such and it's kinda frustrating. I grew up as an Asian guy in America, but more than anything I feel like I identify as just American more than anything. I guess more often than not I do get called in for "non Asian specific" roles, but it also seems weird that I'm expected to fill in as everything else that my skin color denotes as well. I guess it's better than nothing though.