The Serial Monitor window does not allow to do what one expects.
Reference: the Output window: a right-click allows to copy/copy all/ clear and other. Also, a CTRL-A marks everything in Output, and CTRL-C allows to copy it.
Within Serial Monitor (SM):
- a right-click does nothing.
- a CTRL-A marks nothing in the SM, it rather marks everything in the active code window
- a CTRL-C copies everything in the SM currently marked, PROVIDED you can enter CTRL-C fast enough before the next update of SM, because that unmarks everything.
This makes it hard to impossible to use the SM text for a deeper analysis.
What should happen: SM should behave as the same as Output window
Edit: Output has an option to "Turn Auto Scrolling Off". SM needs the same option