Unable to Upload Files with Korean Characters in the Filename

We recently updated our WinSCP from 6.3.6 to 6.5.3 and get the following error message when attempting to upload a file with Korean characters in the filename:

Permission denied
Error Code: 3
Error message from server: Permission denied

We rolled back to version 6.3.6 and confirmed we could upload the files with no issues. We're using SFTP and connecting to an OpenFTP server on the distant end.

I've tried changing the UTF-8 encoding for filenames from Auto to On, and forcing it to use SFTP version 3, and also disabled the transfer to temporary file name option but I can't get it to work.

Thanks for any guidance.