During testing of the new installer, I also tried advanced partitioning using the "Storage editor". I deleted and recreated the partitions with their respective mount points.

Steps to reproduce:

1. Download the Workstation Rawhide ISO with the new installer
2. On the installer's initial screen, click in the top right corner and select "Launch storage editor"
3. Delete the ext4 partition for boot and the Btrfs partition
4. Create a Btrfs partition
5. Create custom subvolumes with their respective mount points: subvolume @ > /; subvolume @home > /home; subvolume @var > /var
6. EFI partition: /boot/efi
7. Click "Return to installation" at the bottom
8. Click install and reboot

On reboot, only the subvolume @ > / is mounted.
The rest of the subvolumes are created but not mounted.

Initially reported in the "feedback collection" discussion: https://discussion.fedoraproject.org/t/feedback-collection-of-test-week-for-the-anaconda-web-ui-installer-for-fedora-workstation/135846/22

Thank you.

Reproducible: Always