A simple program outputs THREE 'Serial.println' lines to the Serial Monitor.
Using an Arduino Uno, three lines are shown and when 'Copy/Pasted' into a Text Editor (Notepad++), there are still three lines.
Using a Teensy 3.5, same three lines are shown, but when 'Copy/Pasted' into the Text Editor, there are instead SIX lines! An extra, empty line (only CR+LF) is added after each "text" line! So, they don't show on the Serial Monitor, only when 'Copy/Pasted'!
Using an Arduino Uno, three lines are shown and when 'Copy/Pasted' into a Text Editor (Notepad++), there are still three lines.
Using a Teensy 3.5, same three lines are shown, but when 'Copy/Pasted' into the Text Editor, there are instead SIX lines! An extra, empty line (only CR+LF) is added after each "text" line! So, they don't show on the Serial Monitor, only when 'Copy/Pasted'!