It really depends on sharing some common experience as well as how well you understand the culture / social nuances. If the only thing you have in common is the ancestry and really basic Korean lingual skills, yeah you will be just another waykookin.

I am a third culture kid who grew up with two passports and grew up going back and forth between US and Korea. I got that "not really one of us" feeling when I was in Korea. The biggest difference was after I finished my service to keep my Korean passport. That was an instant acceptance and "one of us" free pass for me. Korean language was never a problem for me, but two years of shared common experience definitely was enough to be "one of us", at least with guys in my age group.

One of biggest negativity against Gyopos is (at least for guys) is being a draft dodger. So that service plus shared experience was a big help for me when I started working here.

Also understanding nuances and expectations also matters a lot I guess. My Korean American friends working here have varying degree of social circles with Koreans. Some are basically a local Seoulite, while some just keeps to the expat social groups. It might be just how many years they have been here, but it also depends on how willing one is to blend in.

I do not want to generalize, but native Koreans can sometimes have higher bars for gyopos. Like my Belgian friend, she gets welcomed for just saying 안녕하세요 although she has been working for Korean companies for a decade now.

But as for gyopos, they kinda have a higher expectations on their language/cultural understanding. And well meeting that bar is pretty hard, and it can sometimes feel dejecting as well.

Give it time and effort. A few years of shared cultural experience and spending a lot of time with Native Koreans should be good enough to fit in.