How to execute multi-line powershell command

Trying to execute a PowerShell command in asp.net c# but it returns no results, where am I going wrong?

var shell = PowerShell.Create();
var script = $@"$Groups = Get-ADGroup {groupname}; $members = ForEach ($Group in $Groups) {{Get-AdGroupMember -Identity $Group -Recursive}} ; $members | Get-AdUser -Properties Department | Select-Object Name, Department | Sort Department, Name";
shell.Commands.AddScript(script);
var results = shell.Invoke();

foreach (var psObject in results)
{
    dt.Rows.Add(new object[] { psObject.Members["Name"].Value, psObject.Members["Department"].Value });
}

Gridview2.DataSource = dt;
Gridview2.DataBind();

It executes perfectly in PowerShell. Separating the command over lines as per suggested answer does not work.

Edit - I took another look at my powershell and realised that it was unecessarily complicated. I changed it to the below and it now works. Still does not explain why something that returns results in powershell does not work when ran from asp.net.

Get-AdGroupMember -Identity {groupname} -Recursive | Get-AdUser -Properties Department | Select-Object Name, Department | Sort Department, Name