, the datastore capacity looks to be equivalent to what one nodes raw capacity would be here (minus filesystem overhead and/or what it is in TiB vs vendors advertised TB size of disk).
This means that either only 1 node has Disk-Group claimed or your cluster is network partitioned - Quickstart just uses the IP/vmk info provided, I don't think it is aware of whether that network is usable or not.
E.g. you could have usable IPs in same subnet, on vsan-tagged vmk selected BUT these are all attached to a vSwitch with no uplinks attached or connected to switch with ports not configured (e.g. for a configured VLAN).
You can check whether their is a network misconfiguration via:
Cluster > Monitor > vSAN > Skyline Health > retest
If there isn't then check the Disk-Groups via:
Cluster > Configure > vSAN > Disk Management