PowerShell Foreach Loop Not Executing after multiple successful attempts

I've created the following PowerShell function to loop through the files in a user specified directory, marry the CCI values provided by the DISA FSO to the test IDs for each of the STIGs in the directory, and output that data to a .csv file of the users choosing.

The code worked in PowerShell ISE, then I tried it in PowerShell Terminal and it no longer works in either.

When I execute the function, it asks for and stores the parameters however the primary loop does not execute (comment below at line 23). While debugging, I saw that the foreach loop is skipped altogether. What do I need to do to make the foreach loop execute?

Things I've tried:

• moving the param outside the function
• calling the function before or after the function declaration (i.e., at the top or bottom of the script
• removing the check for if the user specified output file exists
• adding a variable after the output file exists check to display the params (this displays -- anything after is skipped)

Current function state:

Function CreateTestPlan {
    param (
        [Parameter(Mandatory = $true, HelpMessage="Filename of DISA STIG Benchmark XCCDF.xml file. Downloaded from IASE website. Usage: -BenchMarksDir")]
        [string]$BenchMarksDir,
        [Parameter(Mandatory = $true, HelpMessage="Filename of DISA CCI .XML file. Downloaded from IASE website. Usages: -CCIFile")]
        [string]$CCIFile,
        [Parameter(Mandatory = $true, HelpMessage="Filename of your choosing, ending in .csv. Usages: -OutFile")]
        [string]$OutFile,
        [Parameter(Mandatory = $true, HelpMessage="Determines output of control numbers and selection. Usages: -CCIFilter + NIST SP 800-53, NIST SP 800-53 Revision 4, NIST SP 800-53A")]
        [ValidateSet("NIST SP 800-53","NIST SP 800-53 Revision 4","NIST SP 800-53A")]
        [string]$CCIFilter
    )

    if (![System.IO.File]::Exists($OutFile))
    {
        New-Item -ItemType file $OutFile -EA Stop
    }
    ElseIf([System.IO.File]::Exists($OutFile))
    {
        Clear-Content $OutFile -EA Stop
    }

    Foreach ($file in $files) #Loop does not execute
    {
        [xml]$Stigx = Get-Content -Path $file.FullName -EA Stop
        [xml]$CCIx = Get-Content -Path $CCIFile -EA Stop

        # start by parsing the xccdf benchmark
        if($Stigx){
            $StigCollection = @()
            # loop through the xccdf benchmark collecting data into an object collection
            $StigName = $Stigx.Benchmark.title
            #loop through each group in the stig
            foreach ($group in $StigX.Benchmark.Group){
                # create a new PSObject collecting and stripping out as required.
                $STIG = New-Object -TypeName PSObject -Property ([ordered]@{
                    GroupID = $group.id
                    RuleTitle = $group.Rule.title 
                    Severity = $group.Rule.severity
                    VulnerabilityDetails = $($($($group.Rule.description) -split '</VulnDiscussion>')[0] -replace '<VulnDiscussion>', '')
                    Check = $group.Rule.check.'check-content'
                    Fix = $group.Rule.fixtext.'#text'
                    ControlIdentifier = $group.Rule.ident.'#text' -join "`r`n"
                    Control = $null # control is null as it will be added from the CCI List
                    StigName = $StigName
                })
                $StigCollection += $STIG
           }# close foreach
        }# close if
        # loop through the Stig Collection updating the Control information pulled from the U_CCI_List.xml
        foreach($StigObj in $StigCollection){
            foreach($CciItem in $CCIX.cci_list.cci_items.cci_item){
                if($CciItem.Id -EQ $StigObj.ControlIdentifier){
                    # filter the control version by the title
                    if($CciItem.references.reference.title -EQ $CCIFilter){
                        $StigObj.Control = $CciItem.references.reference.index -join "`r`n"
                    }
                }
            }
        }
        $StigCollection | Select-Object -Property 'StigName', 'GroupID', 'Control', 'Check' | Export-Csv $OutFile -Append -NoTypeInformation
    }
}

Because adding the test files here caused my browser to crash, I'm providing links to where the necessary parameter files may be downloaded:

Benchmarks: General Operating System STIG CCI Matrix: DISA FSO CCI

Example Usage and No Errors are being recieved: