VCSA UI Installer can be used to deploy vCenter Server Appliance, and it provides various configuration options through the tool's GUI interface including the option to bootstrap a new vSAN cluster("Install on a new vSAN cluster containing the target host).
Due to a technical limitation, the new vSAN cluster bootstrapping option in VCSA UI Installer 9.0 will NOT work, and the deployment process fails at "Install - Stage 2: vCenter Server setup is in progress".
The error seen in the vSAN cluster bootstrapping workflow is a known issue, DO NOT use this option in VCSA UI Installer 9.0.
VMware VCSA UI Installer 9.0
VMware vSAN 9.0