[Kunama]

I wasn't aware that there were fluctuations to the angular tilt of the moon's orbital plane. The lunar orbital plane is tilted 5.145degrees from the ecliptic but I understood that this is a stable tilt.

What is the ecliptic? .... If you were standing deep inside the Earth at its very centre and pointed a laser pointed through the very centre of the Sun and that laser beam then extended through the Sun to the sky beyond, then the line that the laser paints in the sky as the Earth revolves around the Sun is the line of the ecliptic. The lunar orbital plane is at an angle of 5.145 degrees to that imaginary line and due to this difference the lunar orbit dips below the ecliptic for half a lunation.