legal hold assignment api call returning "404" not found

So I have a powershell script which uses an app which is configured to be able to obtain list all of the legal hold objects within the environment. Using this same app, I attempt to obtain the Legal hold assignment objects for each of the legal hold objects. However, whenever I construct and perform the API call, every single return for each of the legal hold objects is "404 not found". Below is the powershell code. Not sure what I am doing wrong, as the code takes the legal hold object id directly from the legal hold api call and plugs it into the legal hold assignment api call, so I know that it is not an issue of mis-typing the id. Note the code utilizes the box command line tool to authenticate and obtain the tokens from the app:

Function get-LegalHold
{
		$token = box tokens get
		$legalurl = 'https://api.box.com/2.0/legal_hold_policies'
		$headers = @{ }
		$headers.Add("Authorization", "Bearer $token")
		Try
		{
			$legalOutput = Invoke-RestMethod -Uri $legalurl -Method get -Headers $headers -ErrorAction Stop
			return $legalOutput
		}
		Catch
		{
			Write-Host $_.Exception.ToString()
			$error[0] | Format-List -Force
		}
}
$obs = (Get-legalhold).entries
$token = box tokens get
		$headers = @{ }
		$headers.Add("Authorization", "Bearer $token")
        Foreach ($ob in $obs)
        {
        $legurl = "https://api.box.com/2.0/legal_hold_policies_assignments?policy_id=$($ob.id)"
        $legurl
		Try
		{
			Invoke-RestMethod -Uri $legurl -Method get -Headers $headers -ErrorAction Stop
		}
		Catch
		{
			Write-Host $_.Exception.ToString()
			$error[0] | Format-List -Force
		}
}

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