Quick3d does not get installed

I just installed 6.4.0 beta1 from the installer for macOS and iOS. (see screenshot)

"Qt Quick 3D" was (and still is) selected to be installed, but none of the files were getting installed: my project's cmake run complained about the cmake module file missing, but after inspecting the 6.4.0 folder, it looks like the whole framework is missing in both the macos and ios folders.

It gets better though: if I then install anything else (an additonal lib or even just the logs), the installer will download 8GB of data, which does include qtquick3d, but also modules like qtwebengine, which were never selected in the first place.