Been having an intermittent problem with our 2012 CX-9 GT. The power lift gate won't always close itself all the way - it leaves it open just enough to set off the "open door" warning, and indeed it isn't fully closed. This happens about half the time when you close the gate via the button on the gate itself. If you close it manually it closes fine. Any ideas on this? I did some quick Googling and found some similar issues relating to sensor strips or something?