Have you seen the recent "boat" trend on TikTok? Where a filter makes the person look like they're on a little boat, and they caption the video something like, "Going back to 'my country' even though I was born in America because Karen told me to"?

Anyway, I think that really highlights this misconception that if any first- or second-gen person goes to their country of ethnic origin — for lack of better phrasing — they'd just seamlessly fit in. But obviously, most of us know the reality: We'd 100% experience culture shock, and people would definitely see us as Americans, not locals.
For example, I'm Korean, and my Korean American friends and I have openly talked about being gyopos. I think the term might have originally meant Koreans who emigrated to another country, but now, it encompasses everyone from half to third-gen Koreans who grew up or live outside of Korea.
To note, I'm mixed, so my experience is both similar and a bit different since I don't present as obviously Korean.
Let's be real, even if you speak Korean (or whichever language), you likely tend to speak some Americanized version of it or probably have enough of an accent that exposes you as not having grown up in Korea (or your 'country of ethnic origin').
One Korean American friend of mine talked about how hard it is to be Korean American in Korea since Koreans expected her to easily assimilate or know what to do.
She felt that since I don't look Korean — and to be fair, I'm not a WASP-East Asian mix, so it's pretty common that people don't even think I'm Asian at all — I don't have the same expectations or standards placed on me by Koreans. And that's fair.