Zone split error message "inaccessible"

I have just got my 2000AWD working. My yard has two thin areas, one North-South and one East-West.  I mapped them separately, but they were combined when the map finalized. I can't find a setting for "mow the long direction", direction is a compass heading. Ok, there is a "Split Zone" function. I will make two zones and set a separate mowing direction.  I get the little red line and split them up.  I drop the line and get "The zone(s) after splitting are inaccessible. Please adjust the separator line."  What does this mean?  I want the zones to be separate, that's the point.  I could add a path between them if that's needed, but all the other places I needed a path it said that and let me add one.  This wants me to move the line, and doesn't seem to know where.  Usually there is a little picture showing what to do, but not here.  The mower doesn't like to mow a narrow strip in the narrow direction as it requires many, many 180° turns.

Hi there, we apologize for the inconvenience.
Overlapping mapping traces while surveying your lawn will cause the two strips to merge into a single continuous zone automatically.
You have two workable solutions:

1. Utilize the dual map feature. Create a separate second map for your other lawn section to prevent them from combining.
2. Leave a noticeable gap between the two areas during mapping. Afterwards, draw a dedicated navigation path to connect them manually.
If this still does not resolve your issue. Would you mind sharing screenshots showing your actual lawn layout on the map along with the inaccessible error message? This will help us visualize your setup and figure out the best way to adjust the zone split line for you.

Here is the error message screenshot.

The map in question will have to wait until tomorrow, I can't upload any more images today according to the website GUI. :-(

I moved the line around, and didn't get the error. It seems like I cut the zone where it was too narrow.  The message didn't say that, so it's still just a theory.