Add Content formatting is wrapping the text.

I have a script that looks through an OU and lists all Security Groups, and the total members of each.

Import-Module ActiveDirectory
$groups = Get-ADGroup -f * -searchbase 'OU to search here'
    foreach ($group in $groups) {
    $groupname=($group.name)
    $membercount=@(Get-ADGroupMember $groupname).count
    $strdone = ($group.name),',',$membercount
    Add-content c:\outputfiles\CountofUsersinEachGroup.txt -value $strdone
}

The output should look like:
SecGroup1,13
SecGroup2,1
SecGroup3,11
SecGroup4,4
SecGroup5,5

But instead, it looks like the follwing:
SecGroup1
,
13
SecGroup2
,
1
SecGroup3
,
11
SecGroup4
,
4

I’ve used Add-Content many times in other scripts in the past and this is the first time it is “wrapping” to a new line.

My other scripts that use Add-Content are working fine (I checked today) so I’m not sure why the formatting is “off” on this one script.

If someone could let me know what I missed I’d appreciate it.