windows-update works intermittently

[barry7evans]

First of all, thank you for maintaining this plugin.
I'm having an issue with Windows Server 2019, where the updates only work some of the time
When they don't work, I am not getting an error. I just see the following:

==> vsphere-iso.WinServer19: Uploading the Windows update elevated script...
==> vsphere-iso.WinServer19: Uploading the Windows update check for reboot required elevated script...
==> vsphere-iso.WinServer19: Uploading the Windows update script...
==> vsphere-iso.WinServer19: Running Windows update...
==> vsphere-iso.WinServer19: Shutting down VM...

I am defining the plug-in, like:

packer {
required_plugins {
windows-update = {
version = "0.14.1"
source = "github.com/rgl/windows-update"
}
}
}

...and then running it by using:

provisioner "windows-update" {
search_criteria = "IsInstalled=0"
filters = [
"include:$true",
]
update_limit = 25
}

I have run my script a number of times sequentially and there seems to be about a 50% success rate.