64-Bit installer doesn't get admin rights correctly

I've compiled the installerframework with MinGW 7.3 and static Qt 5.12.0 (MinGW 7.3), 

then I've created an installer package (offline) for my application.

When I start the installer package without admin rights (64-Bit Windows 10), 

it prompts for admin rights which I then enter but the installer is not able to create the directories under "c:\Program Files", on the other hand, if I run the installer package by right clicking it and select "run as admin" then it works and installs the application correctly.

The uninstaller/maintenance tool only starts if I select "run as admin", it doesn't start if I simply click on it.