showmessage('mymessage') opend 1 of my forms that cannot close unless i exit the application

[alogrep 0]

HI.

This is a mysterious behavior that I had never encountered for decades

I have 2 showmessage(), then a messagedlg, then THIS problematic showmessage, 

   a simple showmessage('mymessage')..

The vcl.dialogs.pas (line 6940 on 12.3)

 

  Result := mrNone;
    if LTaskDialog.Execute then
      Result := LTaskDialog.ModalResult;

when it gets to LTaskDialog.Execute if  shows the message alright but it ALSO makes my custom form visible and I cannot close it in any way. (I must cloe the app)

Any idea on how to ovrcome this behavioiur?