This is a terms of trade shock. The money from chip exports is being recycled back into the US tech cycle, so the currency doesn't strengthen. LNG prices are running through the roof, hurting Korea, Japan, Turkey, India. Policymakers prefer a weaker currency to maintain manufacturing competitiveness with China.
The KOSPI-Korean won correlation is close to zero. Just because a country runs a current account surplus doesn't mean the currency will strengthen. Policy preference is aligned with competitiveness, not currency strength.