When you transfer files between macOS and Windows, filenames in Hangeul (Korean alphabet) may experience that their consonants and vowels are detached from each other on Windows. It is beacuse macOS by default uses NFD for the Unicode representation of filenames.
Please visit the link below to learn more about the text representation of Unicode filenames.
Help » How to change the Unicode normalization form used for filenamesUse BandiNamer for macOS to convert your filenames to NFC, and prevent the consonants and vowels in Hangeul filenames from being detached form each other on Windows.
If you copy & paste the converted files to another folder or rename the files on the Finder, the Unicode forms revert to NFD.