Import not downloading/uploading file attachements

I’m updating a site to a new installation but want to bring over the old posts. I’ve used the export feature on the current site to export the .xml file.

When importing the posts into the new site, I check the box for ‘Download and import file attachments’ and click go. The posts all import fine, but the image attachments are not being downloaded and imported. The posts contain the links to the current site.

I’ve done this many times before on the same server set up… just wondering what the issue could be here. Any help appreciated