Support

Take a look at https://www.akeeba.com/documentation/akeeba-kickstart-documentation/kscantextract.html under Mixed Ownership to understand the problem and https://www.akeeba.com/documentation/akeeba-kickstart-documentation/kstslive.html for the workaround.

However, please note that this kind of server configuration is not compatible with Joomla! 4 and later. In fact, a server configuration where the site's root ownership, your user account (therefore FTP and SFTP), and your web server's user are different UNIX users has been obsolete since the early 2000's – yes, 20 years ago. Especially since the early 2010s not having a screwed up environment like that is trivial, by using PHP-FPM and a different pool for each hosted site, or by using virtualisation. If your host cannot come up with a configuration where the site's root ownership, your user account, and your web server's user are the same UNIX user it's high time to look at a different host.