Qt6 Installation stops on Mac/Big Sur 11.6

[dogen]

I have a new MBAir (M1) and tried to install Qt6 on an external ssd device.

I get this error during the installation process:

Error during installation process (qt.qt6.620.clang_64):
Error while extracting archive "installer://qt.qt6.620.clang_64/6.2.0-0-202109270438qtdeclarative-MacOS-MacOS_11_00-Clang-MacOS-MacOS_11_00-X86_64-ARM64.7z": internal code: E_FAIL

Xcode is installed and I can compile...
I tried the full installation from scratch 2 times but it stops at the same position.
Is the archive broken?