In that case, try setting the following before the Connect-VIServer
[System.Net.ServicePointManager]::SecurityProtocol =[System.Net.SecurityProtocolType]::Tls,
[System.Net.SecurityProtocolType]::Tls11,
[System.Net.SecurityProtocolType]::Tls12
In that case, try setting the following before the Connect-VIServer
[System.Net.SecurityProtocolType]::Tls11,
[System.Net.SecurityProtocolType]::Tls12