Xara Web Designer 15.1.1.54379

Windows 10

Every time export a website to my HDD the index_htm_files always retains files I deleted from the site. For instance, I drag and drop a image.png on the page, change my mind or put in the wrong image, I right-click delete. Even if that image was only on the page for two seconds, the exported folder will have that image in the index folder regardless whether that image (video, audio, etc) is even not used in the site.This is problematic for many reasons including folder size but especially security. I've tried deleting the bitmap gallery, xara backups, searching through the glossary for help. How can I turn this off? If not, why?
How can I delete the files manually if I can't turn it off? Please help. This would make the software almost unusable.