Powershell Issue

I have the following script I am testing and cannot get it to format correctly.

When I run everything from the Sort lline up it works as it should with the grouping.

When I run the entire script the html file created looks terrible and no legible information as below.

Can anyone help.

$a = "<style>"
$a = $a + "BODY{background-color:peachpuff;}"
$a = $a + "TABLE{border-width: 1px;border-style: solid;border-color: black;border-collapse: collapse;}"
$a = $a + "TH{border-width: 1px;padding: 0px;border-style: solid;border-color: black;}"
$a = $a + "TD{border-width: 1px;padding: 0px;border-style: solid;border-color: black;}"
$a = $a + "</style>"



Get-ADComputer -Filter * -Properties * | 
select Name,OperatingSystem,OperatingSystemServicePack | 
Sort-Object Name | Format-Table Name,OperatingSystem -GroupBy OperatingSystem -AutoSize |
ConvertTo-Html |
out-file C:\scripts\test.html

THIS IS THE FILL RUN HTML SAMPLE