Installer fails if requires admin elevation. Cannot extract archives

I've created an installer with Qt IFW, but elevation is required for some operations. 

When running the installer, i always see the following when it tries to download the server artifacts. 

Warning: File does not exist.
[69065] archiveDownloadError : Download Error : Cannot download archive http://<retracted>/1.2.3generic.7z: Cannot download http://<retracted>/1.2.3generic.7z.sha1. Cannot create file "<retracted>/1.2.3generic.7z.sha1":

It doesn't seem to matter where you gainAdminRights, I always see this error.

Steps to Reproduce

1. Have an Azure AD admin account
2. Start installer as non-admin Azure user
3. Progress installer and enter Azure AD admin credentials into UAC prompt
4. Fail

Investigation

• Metadatajob::unzipRepositoryTaskFinished calls QTemporaryDir(..)
• The remoterepo-xxxxx folder created in %temp% has malformed permissions
• When this folder is copied to the installer cache, the admin account cannot extract it.
• See attached picture. 
  • Left is some random file in temp.
  • Right is what QT produces, missing system and administrators. 'Everyone' has no permissions.

 Follow up

The folder and files under \AppData\Local\cache\qt-installer-framework\3deb88fd-c8fc-3bf0-9a89-0f67366893c7\527bef3ad2859a5c9fa4a52e2b88f196fcc431d7 lack admin permissions, causing the error in broken-installer-log-2.txt