I am facing the same situation for a November/December round trip flight from SFO to ICN(KE26) and ICN to SFO(KE25). I purchased my flight in June, then a few weeks later the website shows "Sold Out" for all seating class. Logging into my account, the round trip itinerary is still the same. I called the Korean Air customer service line and the rep said my flight is still scheduled but is sold out at the moment...hmmmm. After trying to explain to the rep of the situation, I gave up and took his word. After further investigation, I see on the website that KE26 and KE 25 shows "Sold Out" for all days from 9/11/24 till the end of the year. These two flights are bookable in January 2025 onward. Can someone advise that is going on and what's my next move to planning purposes.