If a window has both a Close button and an X on the upper right corner, should clicking each of these have the same behavior?
I am working with a vendor file transfer application. There is a windows that allows me to select the file to transfer. Once the file is selected, it launches a second windows to initiate the transfer by clicking Upload or Download. This is the window that has both a close button and the X button. When Close is clicked, it only closes the transfer window but leave the file selector window open. When X is clicked it closes both the transfer windows and the file selector window.
I've asked the vendor to make both button actions consistent (ie. close both windows) but they are telling me this is as designed. My end users are getting confused as leaving the file selector window open makes them think there is another action required. Is it standard best practice to have both Close and X buttons do the same thing?