Virtualmin backup blank "File" in almost all folders that gives an error when extracted

I have setup a Virtualmin backup that appears to be working correctly.

However, when the backups are attempted to be extracted there is a large amount of errors. WinRAR error below:

https://imgur.com/EmADHS6

This appears to be due to blank "Files" in most folders of the backup that WinRAR says cannot be extracted. These "Files" do not appear in Filezilla when browsing to the same directory on the server. Please see the images for more information:

https://imgur.com/TcfwXJp

https://imgur.com/M6mKCmq

Does anyone know what these files may be, and whether this is normal, including receiving many errors when extracting the backup?

Thank you