Clearing Dynamic FMX listview bitmaps from memory

I recently started working with dynamic listview items. It's great except for when I try to add and clear items with bitmaps. I have a listview where I add items and download the image into a memstream and assign it to the bitmap of the dynamic listview item. This works except for when I go and clear all the items with lv.items.clear it does not get removed from memory.

The memory just keeps rising even though I clear the old items. Is there a ways to clear all the bitmaps?

Basically what happens is:

1. Populate dynamic listview with 10 items. Add data and bitmaps.
2. Look at memory. Went up with 2 megabytes.
3. Clear the listview with lv.items.clear.
4. Look at memory. No change?
5. Repeat and the memory just goes up and up.

I have tried looping through all the listview items and setting each bitmap to nil but no result in any memory change. I also tried freeing each item by looping through it but it just crashes the app.

Should I be clearing all the items or bitmaps in a way? If so how can I go about doing that?

Here's how I'm loading all of the items:

procedure TPluginInstaller.Load;
begin
  with frmMain.framePluginManager do
  begin
    TThread.CreateAnonymousThread(
      procedure
      begin
        var restClient := TRESTClient.Create(nil);
        var restRequest := TRESTRequest.Create(nil);
        var restResponse := TRESTResponse.Create(nil);
        try
          restRequest.Client := restClient;
          restRequest.Response := restResponse;

          restClient.BaseURL := BASE_URL;
          restClient.UserAgent := APP_USERAGENT;
          restRequest.AddParameter('query', fQuery);
          restRequest.AddParameter('page', fPage.ToString);
          restRequest.AddParameter('sort', SortBy[fSort]);

          if fSort = 0 then
            restRequest.AddParameter('sortdir', 'asc')
          else
            restRequest.AddParameter('sortdir', 'desc');

          restRequest.AddParameter('categories[]', 'rust');

          restRequest.Execute;

          var jdata := restResponse.JSONValue;

          fLastPage := jdata.GetValue<Integer>('last_page', 1);
          fPage := jdata.GetValue<Integer>('current_page', 1);

          TThread.Synchronize(nil,
            procedure
            begin
              spnedtPage.Max := fLastPage;
              spnedtPage.Value := fPage;
              lblPageMax.Text := ' of ' + fLastPage.ToString;

              lvPluginInstaller.BeginUpdate;
              try
                lvPluginInstaller.Items.Clear;

                for var jplugins in (jdata.FindValue('data') as TJSONArray) do
                begin
                  var aItem := lvPluginInstaller.Items.Add;

                  var aIcon := aItem.Objects.FindObjectT<TListItemImage>('Icon');
                  var aDownloadsIcon := aItem.Objects.FindObjectT<TListItemImage>('DownloadsIcon');
                  var aVersionIcon := aItem.Objects.FindObjectT<TListItemImage>('VersionIcon');
                  var aAuthorIcon := aItem.Objects.FindObjectT<TListItemImage>('AuthorIcon');
                  var aUpdatedIcon := aItem.Objects.FindObjectT<TListItemImage>('UpdatedIcon');

                  var aTitle := aItem.Objects.FindObjectT<TListItemText>('Title');
                  var aDescription := aItem.Objects.FindObjectT<TListItemText>('Description');
                  var aVersion := aItem.Objects.FindObjectT<TListItemText>('Version');
                  var aDownloads := aItem.Objects.FindObjectT<TListItemText>('Downloads');
                  var aAuthor := aItem.Objects.FindObjectT<TListItemText>('Author');
                  var aURL := aItem.Objects.FindObjectT<TListItemText>('URL');
                  var aUpdated := aItem.Objects.FindObjectT<TListItemText>('Updated');

                  GetIcon(jplugins.GetValue<string>('icon_url').Trim, aIcon);

                  aDownloadsIcon.ImageIndex := 0;
                  aVersionIcon.ImageIndex := 1;
                  aAuthorIcon.ImageIndex := 2;
                  aUpdatedIcon.ImageIndex := 4;

                  aTitle.Text := jplugins.GetValue<string>('title', 'Unknown Plugin Title');
                  aDescription.Text := jplugins.GetValue<string>('description', 'Unknown Plugin Description');
                  aVersion.Text := jplugins.GetValue<string>('latest_release_version_formatted', 'Unknown Version');
                  aDownloads.Text := jplugins.GetValue<string>('downloads_shortened', 'Unknown Downloads');
                  aAuthor.Text := jplugins.GetValue<string>('author', 'Unknown Author');
                  aURL.Text := jplugins.GetValue<string>('json_url', 'Unknown URL');
                  aUpdated.Text := jplugins.GetValue<string>('latest_release_at', 'Unknown');
                end;
              finally
                lvPluginInstaller.EndUpdate;
              end;
            end);

        finally
          restResponse.Free;
          restRequest.Free;
          restClient.Free;
        end;
      end).Start;
  end;
end;

Loading bitmaps from url:

procedure TPluginInstaller.GetIcon(const aURL: string; aIcon: TListItemImage);
begin
  if aURL = '' then
  begin
    aIcon.ImageIndex := 3;
    Exit;
  end;

  TThread.CreateAnonymousThread(
    procedure
    begin
      var imgStream := TMemoryStream.Create;
      try
        TDownloadURL.DownloadRawBytes(aURL, imgStream);

        TThread.Synchronize(nil,
          procedure
          begin
            aIcon.Bitmap := TBitmap.CreateFromStream(imgStream);
          end);

      finally
        imgStream.Free;
      end;
    end).Start;
end;