Textbox does not respect Environment.NewLine because reasons

[Trolldemorted]

tl;dr uwp is strange: https://social.msdn.microsoft.com/Forums/sqlserver/en-US/a30e0caa-d9f4-4b3f-9d43-b9e45544fb84/uwp-textbox-newline-changes-between-sdk-10240-and-14393?forum=wpdevelop

Even if you copypaste text with \r\n, messageTextBox.Text contains only \r.