Apple Watch 6 - Crown malfunction (Not recognizing my finger) during ECG

Hi, I was using my Apple Watch 6 since November, and my watch was working great for me until now, but now I'm having this issue. 3 days ago, trying to get my ECG and crown doesn't recognize my finger.

Not recognizing my finger at all when I gently put my finger on the crown.

I can push the button hard till it clicks, then it recognize for a 5~10 secs but it got fails to recognize my finger after that.

I tried un-pair and re-paired to my iPhone and the problem still there.

except for the crown, watch works fine.

any suggestions? I'm at USAG - Humphreys at South Korea, so there's not really a big apple store that I can go to fix it. and I would really like to fix it by something that I can try out. thanks!