Unable to suppress PSAvoidLongLines warning in a method

I'm unable to suppress the PSAvoidLongLines warning in a method inside a class.

Steps to reproduce

Run Invoke-ScriptAnalyzer -Path . -Recurse while the following PSScriptAnalyzerSettings.psd1 file is present in the folder:

@{
  Severity     = @('Error', 'Warning', 'Information')
  ExcludeRules = @('PSUseBOMForUnicodeEncodedFile',
    'PSAvoidUsingConvertToSecureStringWithPlainText',
    'PSAvoidUsingPlainTextForPassword')
  Rules        = @{
    PSAlignAssignmentStatement = @{
      Enable         = $true
      CheckHashtable = $true
    }
    PSPlaceCloseBrace          = @{
      Enable             = $true
      NoEmptyLineBefore  = $false
      IgnoreOneLineBlock = $true
      NewLineAfter       = $true
    }
    PSPlaceOpenBrace           = @{
      Enable             = $true
      OnSameLine         = $true
      NewLineAfter       = $true
      IgnoreOneLineBlock = $true
    }
    PSAvoidLongLines           = @{
      Enable            = $true
      MaximumLineLength = 80
    }
  }
}

Class foo {
  [Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSAvoidLongLines", "")]
  [String]output () {
    $output = "a book is a book is a book. but this report on the activities of a company is"
    return $output
  }
}

Expected behavior

0 warnings

Actual behavior

RuleName                            Severity     ScriptName Line  Message
--------                            --------     ---------- ----  -------
PSAvoidLongLines                    Warning      test.ps1   4     Line exceeds the configured maximum length of 80 characters
1 rule violations found.    Severity distribution:  Error = 0, Warning = 1, Information = 0

If an unexpected error was thrown then please report the full error details using e.g. $error[0] | Select-Object *

Environment data

> $PSVersionTable
Name                           Value
----                           -----
PSVersion                      7.0.3
PSEdition                      Core
GitCommitId                    7.0.3
OS                             Darwin 17.7.0 Darwin Kernel Version 17.7.0: Wed May 27 17:00:02 PDT 2020; root:xnu-4570.71.80.1~1/RELEASE_X86_64
Platform                       Unix
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

> (Get-Module -ListAvailable PSScriptAnalyzer).Version | ForEach-Object { $_.ToString() }
1.19.0

See also #1586 for initial report since this issue was closed i opened a new one and provided clear repo steps.