Lyx 2.1.2 on Windows 7: When I do File/New document, it opens up with change-tracking switched on, so that I start typing and then have to undo it and turn off change-tracking and start again. Not life-threatening, but annoying... and I can't find where to control this behaviour.
If it's not just me, then Tools/Preferences/Look&Feel/Document handling could be a good place for a checkbox to turn this off/on for new documents. Mark