Self shading orientation depends on diodes?

In the Self Shading Calculator for Fixed Tilt Arrays:

Why should the number of bypass diodes depend on the orientation of the module relative to the ground? I see the need to specify whether the diodes are isolating areas along the length verses areas along the width of the panel. But why does a warning dialog pop up when I change the orientation? I'm not changing the electrical connections of the diodes by rotating the panel 90 degrees.

For example: a 6x10 = 60 cell panel with 3 diodes will pop up a warning if I try to rotate it so that it's long side is parallel to the ground (landscape orientation). Why? The only way to make this warning not show is to specify 10 cells along the width, but then of course the width would be greater than the length which conflicts with the help instructions and the diagram.

How is this meant to work?

Thanks,
Kelley

Another self shading comment:

I tested the PV Shading Slope E/W and found that negative values create power drops in the afternoon. This is consistent with slopes that are low at the E end and high at the W end, causing afternoon shadows among rows.

This seems to be the opposite of the definition in the SAM help:
An east-west slope of 10 degrees would be inclined uphill from east to west at a 10 degree angle from horizontal.

A value of positive 10 in SAM will show power drops in the mornings. And I believe the definition describes a slope that is low at the E end and high at the W end. The power should drop in the afternoon.

Best,
Kelley