I'm running NoesisGUI on Windows machine in Unity.
The behaviour is observed on any TextBox with AcceptsReturn=True.
Type some multiline text - Text property would contain \n as a line break instead of \r\n.
Copy typed text from TextBox into any text editor (e.g. Notepad++ - it allows to see unprintable symbols' codes) - pasted text would contain \r\n for line breaks.
Copy the same text from editor back into TextBox - Text property contains \r\n, but TextBox starts to behave strangely: selection is drawn incorrectly, sometimes cursor is placed in incorrect position.