TDBPlannerMonthView

I have a repeatable item Subject 9. This is not displayed on 1/14/2021. ShowScrollColumn is True. Am I missing something?

Nothing?

When there is only this little information, I cannot say anything useful.
Recurrency rule? (A pure guess you use this as you don't tell it)
DBPlannerMonthView event handlers?
DBPlannerMonthView property settings?
Other code?
DB record contents?

I'm very sorry, but if even the most basic essential information to decipher your problems is missing, I cannot help you.

I specify that I am only interested in displaying invisible items.
The scroll buttons appear in a right side column, made visible with ShowScrollColumn set to true.
ShowScrollColumn is True. Right side column is not displayed

Recurrency rule? (A pure guess you use this as you don't tell it)
It's OK. The recurring item is displayed - clAqua.

DBPlannerMonthView property settings?
In Attachment. Now I have, for sure, displayed only two items. In the first picture you can see three items.

Other code?
Not relevant for the issue.

DB record contents?
In Attachment.

DBPlannerMonthView event handlers?

procedure TfrmPlannerRole.dbpmwMonthCreateKey(Sender: TObject; APlannerItem: TPlannerItem; var Key: string);
begin
  APlannerItem.Text.Text := 'Vytvorené programovo';
  APlannerItem.Tag := -1;
  APlannerItem.Shape := TPlannerShape(0);
  APlannerItem.CaptionType := TCaptionType(1);
  APlannerItem.DBKey := '-1';
  APlannerItem.Update;
  fdtblPlanner.Insert;
end;

procedure TfrmPlannerRole.dbpmwMonthFieldsToItem(Sender: TObject; Fields: TFields; Item: TPlannerItem);
const
  Recurrent = 0;
begin
  if not Fields.FieldByName('COLOR').IsNull then
  begin
    Item.Color := TColor(Fields.FieldByName('COLOR').AsInteger);
    Item.ColorTo := Item.Color;
    Item.CaptionBkg := jstpnlWeekProperties.Color;
    Item.CaptionBkgTo := jstpnlWeekProperties.ColorTo;
  end;

  if Fields.FieldByName('SHAPE').AsInteger < Shift then
  begin
    Item.DrawTool := nil;
    Item.Shape := TPlannerShape(Fields.FieldByName('SHAPE').AsInteger);
    Item.Tag := -1;
  end
  else
  begin
    Item.DrawTool := FRolePlanner.ShapeDrawTool[Fields.FieldByName('SHAPE').AsInteger - Shift];
    Item.Shape := psTool;
    Item.Tag := Fields.FieldByName('SHAPE').AsInteger - Shift;
  end;

  if Item.Recurrent then
    Item.ImageID := Recurrent
  else
  begin
    if Fields.FieldByName('IMAGE').IsNull then
      Item.ImageID := -1;
  end;

  Item.CaptionType := TCaptionType(Fields.FieldByName('CAPTIONTYPE').AsInteger);
  Item.Alarm.Active := TBasicFunction.IntToBool(Fields.FieldByName('ALARMACTIVE').AsInteger);
  Item.Alarm.Address := Fields.FieldByName('ALARMADRRESS').AsString;
  Item.Alarm.Message := Fields.FieldByName('ALARMMESSAGE').AsString;
  Item.Alarm.NotifyType := TAlarmNotifyType(Fields.FieldByName('ALARMNOTIFYTYPE').AsInteger);
  Item.Alarm.Time  := TAlarmTime(Fields.FieldByName('ALARMTIME').AsInteger);
  Item.Alarm.TimeAfter := Fields.FieldByName('ALARMTIMEAFTER').AsDateTime;
  Item.Alarm.TimeBefore := Fields.FieldByName('ALARMTIMEBEFORE').AsDateTime;
  Item.URL := Fields.FieldByName('URL').AsString;
  Item.Flashing := TBasicFunction.IntToBool(Fields.FieldByName('FLASHING').AsInteger);
end;

procedure TfrmPlannerRole.dbpmwMonthItemToFields(Sender: TObject; Fields: TFields; Item: TPlannerItem);
begin
  if Item.DBKey = '' then
  begin
    Item.DBKey := IntToStr(NewPrimaryKey);
    Fields.FieldByName('SUBJECT').AsString := 'Predmet nie je určený';
  end;

  Fields.FieldByName('IDPLANNERS').AsInteger := StrToInt(Item.DBKey);
  Fields.FieldByName('COLOR').AsInteger := Item.Color;
  Fields.FieldByName('CAPTIONTYPE').AsInteger := Ord(TCaptionType(Item.CaptionType));
  Fields.FieldByName('IMAGE').AsInteger := Item.ImageID;

  Fields.FieldByName('ALARMACTIVE').AsInteger := TBasicFunction.BooleanToInt(Item.Alarm.Active);
  Fields.FieldByName('ALARMADRRESS').AsString := Item.Alarm.Address;
  Fields.FieldByName('ALARMMESSAGE').AsString := Item.Alarm.Message;
  Fields.FieldByName('ALARMNOTIFYTYPE').AsInteger := Ord(TAlarmNotifyType(Item.Alarm.NotifyType));
  Fields.FieldByName('ALARMTIME').AsInteger := Ord(TAlarmTime(Item.Alarm.Time));
  Fields.FieldByName('ALARMTIMEAFTER').AsDateTime := Item.Alarm.TimeAfter;
  Fields.FieldByName('ALARMTIMEBEFORE').AsDateTime := Item.Alarm.TimeBefore;
  Fields.FieldByName('URL').AsString := Item.URL;
  Fields.FieldByName('Flashing').AsInteger := TBasicFunction.BooleanToInt(Item.Flashing);

  if Item.Tag > -1 then
    Fields.FieldByName('SHAPE').AsInteger := Item.Tag + Shift
  else
    Fields.FieldByName('SHAPE').AsInteger := Ord(TPlannerShape(Item.Shape));
end;

Planner MonthView 2021 01 14

TDBPlannerMonthView Settings 2

Please send a full source code project that can be compiled with a clear step by step description of how to reproduce the problem with your project.
I cannot puzzle together something from screenshots of object inspectors, partial code snippets, screenshots of table contents,...

Please
A Pokusy.zip (28.6 KB)

I'm still attaching
A Pokusy dpr(oj).zip (2.5 KB)

I test this here and the item with "Subject 9" is where it is expected to be on Jan 14

Yes, that's fine. But on Jan 14 there are a total of 4 active items. Only two can be displayed. It's OK. But the buttons for items not displayed are not displayed!