Depending on the Chart width and what points have labels, the bottom axis doesn't show the labels.

uses Series;

var Chart1: TChart;

procedure TForm1.FormCreate(Sender: TObject);

  function IsNumberInArray(const ANumber: integer;
  const AArray: array of integer): boolean;
  var
    i: integer;
  begin
    for i := Low(AArray) to High(AArray) do
      if ANumber = AArray[i] then
        Exit(true);
    result := false;
  end;

var i, c: Integer;
begin
  Chart1:=TChart.Create(Self);
  Chart1.Parent:=Self;

  Chart1.Width:=538;
  Chart1.Height:=296;

  c:=0;
  with Chart1.AddSeries(TLineSeries) do
    for i:=1 to 723 do
      if IsNumberInArray(i, [2,36,96,156,216,276,336,396,455,515,575,635,695]) then
      begin
        Add(50,IntToStr(c));
        Inc(c);
      end
      else
        Add(50);
end;

Reproduced in v2016.19. Works fine in v2016.18.
"Speed fix" changes affecting this: ea504ca and 8b371e8 in git.