Windscreen, windshield wipers not calibrated properly.

Minor quirk ... anyone else have the problem in rain (doh) ... that the wipers hit the top part of the drivers side of the windscreen?

Have you checked the shaft bolt? Maybe it's loose and the driver side arm has jump one notch. I don't think there is any calibration or sensors involved here. If you find that the wiper doesn't go back down as far as it should it's probably it. On mine, when it's idle, both ends of each wipers are pretty much aligned.

I drive a 2011 leaf. I just noticed that the OE wiper blades appear to be 28 in long, and every website I find shows 26 in length for replacement blades. Is your blade hitting the top edge of the windshield, or the "a-pillar" side of the windshield? I am unclear on that from your post. The OE blades have an offset, where the replacement blades don't. That may be how they are able to accommodate the extra length on the blades. I don't think my blades hit the edge of my windshield, though.