Sonarr only updates media file dates, run this to fix season and series folder dates.

fix_season_series_lmt.ps1

$dir = get-childitem -path E:\tv -directory -Exclude "*sonar*"

foreach ($series in $dir){
        $show = get-item $series
        $show_lwt = $show.LastWriteTime

        $seasons = get-childitem -directory $series
        foreach ($season in $seasons){
                $showseason = get-item "$series\$season"
                $season_lwt = $showseason.LastWriteTime
                $episodes = Get-ChildItem $showseason -filter *.m*
                foreach ($episode in $episodes){
                        $efile = get-item "$series\$season\$episode"
                        if ($efile | Test-Path) { $episode_lwt = $efile.LastWriteTime }
                }
                if (!($episode_lwt -eq $season_lwt)) {
                        Write-Host "Changing $showseason From $season_lwt To $episode_lwt"
                        $showseason.LastWriteTime = $episode_lwt
                }
        }
        if (!($episode_lwt -eq $show_lwt)) {
                Write-host "Changing $show From $show_lwt To $episode_lwt"
                $show.LastWriteTime = $episode_lwt
        }
}