c# wpf Dialog will close the owner window - reactjs

Question

i have a window that is acting like a Dialog with two buttons and a textbox, so its an input dialog, the problem is when i press the buttons, or close the dialog window in any way the main window that i used to create this dialog will get closed too! (exit code = 0) and another thing is that it will work OK in vs debugging but when i run the app without vs debugging that owner window get closed and in my case that window is the Main app window so the whole application will shutdown! what am i doing wrong?
XAML:
<Window x:Class="Server.Forms.Dialogs.PokeDialog"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:Server.Forms.Dialogs"
mc:Ignorable="d"
Title="Poke" MinHeight="120" MinWidth="225"
ResizeMode="CanResizeWithGrip"
SizeToContent="WidthAndHeight"
x:Name="windowPoke"
Loaded="windowPoke_Loaded">
<StackPanel VerticalAlignment="Stretch"
HorizontalAlignment="Stretch"
Margin="25">
<Label Content="Poke Reason:"
Padding="0"/>
<TextBox x:Name="textboxPokeReason"
Margin="0 5"/>
<DockPanel>
<Button x:Name="btnOk"
Click="btnOk_Click"
IsDefault="True"
Content="OK"
MinWidth="100"
Margin="0 0 5 0"/>
<Button x:Name="btnCancel"
Click="btnCancel_Click"
IsCancel="True"
Content="Cancel"
MinWidth="100"/>
</DockPanel>
</StackPanel>
C#:
public partial class PokeDialog : Window
{
public string PokeReason
{
get { return textboxPokeReason.Text; }
}
public PokeDialog()
{
InitializeComponent();
}
private void windowPoke_Loaded(object sender, RoutedEventArgs e)
{
textboxPokeReason.Focus();
}
private void btnOk_Click(object sender, RoutedEventArgs e)
{
DialogResult = true;
}
private void btnCancel_Click(object sender, RoutedEventArgs e)
{
DialogResult = false;
}
}
the way i used dialog:
private void btnPokeClient_Click(object sender, RoutedEventArgs e)
{
var dialog = new PokeDialog();
if (dialog.ShowDialog() == true)
{
MessageBox.Show("TRUE - input text:" + dialog.PokeReason);
}
else MessageBox.Show("FALSE");
}
i can see the messageboxes too, but after closing this message boxes the whole app will get closed