i had the same issue and got the valve replaced (with an ebay part...) by a shady AC shop. They still charged me a couple hundred dollars, and said that they generally just replace compressors. There were a few Kias there too. Performance is better but it's not 100%. I still get not-as-cold air on occasion. Hard to tell if it's the valve or what. The connector/harness that plugs into the valve looked pretty chewed up too on the inside for what it's worth and I ordered a replacement (found one on AliExpress) but haven't changed it out yet.
It doesn't seem to be an issue isolated to Kia/Hyundai, check out this VW video
It doesn't seem to be an issue isolated to Kia/Hyundai, check out this VW video
