This is a issue that has been there from the start. The problem is that the headlights are tracked as movement especially on mains powered cams. It seems be more prevalent on wet days where additional reflections come into play as well. There does not seem to be any way to remediate this apart from angling the cam, adjusting zones or if there is a future motion algorithm update. The problem would be that is headlights are somehow ignored, one could simply shine a light on the cam and walk up to it without trigging a motion.
It should be noted that, unfortunately in some cases an outlook is not suitable for Ring or maybe any cams at all based on local positioning and conditions.