Struggling with FTP / SFTP backup from WHM..??

I have an FTP server configured with both FTPS and SFTP enabled: From FileZilla I am able to connect using either option, and I can create files/folders, and delete them no problem. From a WordPress site running Updraft Plus I am able to use the FTPS option successfully (only if I disable passive mode.) From WHM I don't see an option for FTPS. I tried using the FTP option with my FTPS port 2134, but that gives me an immediate error that it "cannot connect to 'server' using provided credentials." If I try FTP with my SFTP port of 2222 then it hangs for 30 seconds and gives me a timeout error. If I try SFTP with my port 2222, then it actually creates the validate.tmp file on the server, but it fails with an error that it "couldn't delete remote file: permission denied." Again, though, I can use the same setup with FileZilla and I can delete those files just fine. So it seems like I'm closest with SFTP, and it's connecting and creating a file, but then it can't delete the file. Any idea why that would be? Any information on this would be greatly appreciated. Thanks!