Results missing - queries always not complete

<#
	.SYNOPSIS
	    This Script is gets all registered Firewalls from Sophos Central via the API

	.PARAMETER ClientID
	    The Client-ID from Sophos-Central API-Management

	.PARAMETER ClientSecret
	    The Secret for the ClientID
#>
param (
	[Parameter(Mandatory)]
	[string] $ClientID,

	[Parameter(Mandatory)]
	[string] $ClientSecret
)

function Get-SophosAccessToken() {
	param (
		[Parameter(Mandatory)]
		[string] $ClientID,

		[Parameter(Mandatory)]
		[string] $ClientSecret
	)

	$headers = New-Object "System.Collections.Generic.Dictionary[[String],[String]]"
	$headers.Add("Content-Type", "application/x-www-form-urlencoded")
	$body = -join("grant_type=client_credentials&scope=token&client_id=", $ClientID, "&client_secret=", $ClientSecret)
	$response = Invoke-RestMethod 'https://id.sophos.com/api/v2/oauth2/token' -Method 'POST' -Headers $headers -Body $body

	$response.access_token
}

function Get-SophosPartnerId() {
	param (
		[Parameter(Mandatory)]
		[string] $AccessToken
	)

	$headers = New-Object "System.Collections.Generic.Dictionary[[String],[String]]"
	$headers.Add("Authorization", (-join("Bearer ", $AccessToken)))
	$response = Invoke-RestMethod 'https://api.central.sophos.com/whoami/v1' -Method 'GET' -Headers $headers

	$response.id
}

function List-SophosTenants() {
	param (
		[Parameter(Mandatory)]
		[string] $PartnerID,

		[Parameter(Mandatory)]
		[string] $AccessToken,

		[int] $PageNumber = 1
	)

	$headers = New-Object "System.Collections.Generic.Dictionary[[String],[String]]"
	$headers.Add("X-Partner-ID", $PartnerID)
	$headers.Add("Authorization", (-join("Bearer ", $AccessToken)))
	$headers.Add("Accept", "application/json")
	$response = Invoke-RestMethod (-join("https://api.central.sophos.com/partner/v1/tenants?page=", $PageNumber, "&pageSize=100&pageTotal=true")) -Method 'GET' -Headers $headers

	# Save all tenant IDs in a list/map with the name of the tenant
	$tenants = @{}
	foreach ($tenant in $response.items) {
		$tenants.add( $tenant.id, [pscustomobject]@{
			Id = $tenant.id
			Name = $tenant.name
			APIDataRegion = $tenant.dataRegion
		})
	}

	$page = $response.pages.current
	if ($page -lt $response.pages.total) {
		$nextPage = $page + 1
		$results = List-SophosTenants -PartnerID $PartnerID -AccessToken $AccessToken -PageNumber $nextPage
		foreach ($key in $results.Keys) {
			$tenants.add($key, $results[$key])
		}
	}

	$tenants
}

function Get-SophosFirewalls() {
	param (
		[Parameter(Mandatory)]
		[string] $TenantID,
		[string] $TenantName,

		[string] $DataRegion = "eu2",

		[Parameter(Mandatory)]
		[string] $AccessToken
	)

	$headers = New-Object "System.Collections.Generic.Dictionary[[String],[String]]"
	$headers.Add("X-Tenant-ID", $TenantID)
	$headers.Add("Authorization", (-join("Bearer ", $AccessToken)))
	$headers.Add("Accept", "application/json")
	try {
		$response = Invoke-RestMethod (-join("https://api-", $DataRegion, ".central.sophos.com/firewall/v1/firewalls")) -Method 'GET' -Headers $headers
	} catch {
		Write-Host (-join("**** Error on Tenant: ", $TenantName, " (", $TenantID, ") in Data-Region ", $DataRegion, " ****`n"))
		return
	}

	$firewalls = @{}
	foreach ($firewall in $response.items) {
		$firewalls[$firewall.id] = @([pscustomobject]@{
			Id = $firewall.id
			Name = $firewall.name
			HostName = $firewall.hostname
			Version = $firewall.firmwareVersion
			Model = $firewall.model
			PublicIpv4 = $firewall.externalIpv4Addresses[0]
		})
	}

	$firewalls
}

$AccessToken = Get-SophosAccessToken -ClientID $ClientID -ClientSecret $ClientSecret
$PartnerID = Get-SophosPartnerId -AccessToken $AccessToken
$Tenants = List-SophosTenants -PartnerID $PartnerID -AccessToken $AccessToken

foreach ($Tenant in $Tenants.Values) {
    $Firewalls = Get-SophosFirewalls -TenantID $Tenant.Id -AccessToken $AccessToken -DataRegion $Tenant.APIDataRegion -TenantName $Tenant.Name

    if ($Firewalls.Values.count -gt 0) {
        $date = Get-Date -Format "dd.MM.yyyy"
        $fileName = "FirewallInformationen_$date.txt"

        $output = "Tenant: $($Tenant.Name)`r`n"
        $output += "Id: $($Tenant.Id)`r`n"
        foreach ($Firewall in $Firewalls.Values) {
            $output += "`tId: $($Firewall.Id)`r`n"
            $output += "`tName: $($Firewall.Name)`r`n"
            $output += "`tHostname: $($Firewall.HostName)`r`n"
            $output += "`tVersion: $($Firewall.Version)`r`n"
            $output += "`tModel: $($Firewall.Model)`r`n"
            $output += "`tIpv4: $($Firewall.PublicIpv4)`r`n"
            $output += "`r`n"
        }
        $output | Out-File -FilePath $fileName -Append
    }

}
pause