Did you use “Exclude Media Files” or “Exclude Web Files“? If the file in question is a media file, then this is the expected behavior. If you want that particular file to be encrypted, you can create a custom exclusion list instead on our predefined options. use “Exclude the Following Files“, and build your app again.
Did you use “Exclude the Following Files“? if the files match the patterns, then this is the expected behavior. You can refine the exclude list of your app, and build again.