backup is successful but file not created

I’m exporting site as a file. Export process is successfully finishes, and green Download button is showing up. But when I’m clicking it, browser is showing an error “File is not available on the server”. When I’m navigation to wp-content/ai1wm-backups folder, there is no *.wpress files there.

Just in case, I’m trying to backup a site on the staging environment on Hostinger (maybe it has something to do with the problem)