Terraform will not create VMs for master and worker for upi vsphere when unset var.control_plane_ip_addresses and var.compute_ip_addresses. When users are using IPAM (as before) to reserve IPs instead of setting static IPs directly into var.control_plane_ip_addresses and var.compute_ip_addresses, Based on upstream code #1 and #2. The count of master and worker is always 0, then terraform will not create any VMs for master and worker nodes. If we changed code as below, it works in IPAM case as before.  
control_plane_fqdns = [for idx in range(length(var.control_plane_ip_addresses)) : "control-plane-${idx}.${var.cluster_domain}"]  
compute_fqdns = [for idx in range(length(var.compute_ip_addresses)) : "compute-${idx}.${var.cluster_domain}"] ==>>
control_plane_fqdns = [for idx in range(var.control_plane_count) : "control-plane-${idx}.${var.cluster_domain}"]
compute_fqdns = [for idx in range(var.compute_count) : "compute-${idx}.${var.cluster_domain}"]

4.13.0-0.nightly-2023-03-11-033820

always

1.Trigger job to install a cluster on vSphere with upi.
2.If the ip applied for master and worker VMs from IPAM server instead of setting the static ip directly into var.control_plane_ip_addresses and var.compute_ip_addresses, the VM creation will fail. 

the VM creation will fail

VM creation succeeds.

#1 link:https://github.com/openshift/installer/blob/master/upi/vsphere/main.tf#L15-L16
#2 link:https://github.com/openshift/installer/blob/master/upi/vsphere/main.tf#L211
This bug will only affect UPI vSphere installation when user use IPAM server to reserve static IPs instead of setting static ip directly into var.control_plane_ip_addresses and var.compute_ip_addresses. now it don't affect QE test, because we still install with previous code.