How to add more than two devices with PowerCLI - powercli

Question

I am trying to setup hardware passthrough on a ESXi 6.0 server with the following PowerCLI script:
Connect-VIServer $server -User $user -Password $pwd
$AllVirtualMachines = Get-VM -Location "Dev Machines"
foreach ($VirtualMachine in $AllVirtualMachines)
{
Get-PassthroughDevice -VM $VirtualMachine | Remove-PassthroughDevice -Confirm:$false
}
foreach ($VirtualMachine in $AllVirtualMachines)
{
$PciDeviceList = Get-PassthroughDevice -VMHost 172.16.7.130 -Type Pci
Add-PassthroughDevice -VM $VirtualMachine -PassthroughDevice $PciDeviceList[0] -Confirm:$false
}
foreach ($VirtualMachine in $AllVirtualMachines)
{
$PciDeviceList = Get-PassthroughDevice -VMHost 172.16.7.130 -Type Pci
Add-PassthroughDevice -VM $VirtualMachine -PassthroughDevice $PciDeviceList[1] -Confirm:$false
}
foreach ($VirtualMachine in $AllVirtualMachines)
{
$PciDeviceList = Get-PassthroughDevice -VMHost 172.16.7.130 -Type Pci
Add-PassthroughDevice -VM $VirtualMachine -PassthroughDevice $PciDeviceList[2] -Confirm:$false
}
foreach ($VirtualMachine in $AllVirtualMachines)
{
$PciDeviceList = Get-PassthroughDevice -VMHost 172.16.7.130 -Type Pci
Add-PassthroughDevice -VM $VirtualMachine -PassthroughDevice $PciDeviceList[3] -Confirm:$false
}
...and it works great...for two devices. After any two PCI devices are setup with a hardware passthrough I will be given a message of "The maximum number of PCI devices has been reached". However I can go in via the GUI and add all the PCI devices I want...I've had as many as nine devices on one VM.
The devices I am trying to add are NVMe drives if it matters.