Strange coverage pattern on DS40F mapping

Hello World,

I am working on a project for a local school and dropped in some DS40F speakers to evaluate their coverage.
After I looked at the 1-4 kHz avg. coverage, I took a look at the coverage at individual frequencies and saw some anomalies that I normally don’t see in a single driver speaker. The pattern of the DS40F should be conical at all frequencies but instead shows a non-symmetrical pattern (see the attached screen shot of the loudspeaker database and the coverage map).
The floor does slope steeply in this room so I can predict that it may not be symmetrical because of that but I do not expect what I am seeing to be correct. I moved them back to a flat floor in the rear of the room and it still does not look right. Finally, I replace one of the DS40F with a DS40SE and I got the coverage pattern I expected (I used a 8 ohm version to match the levels)
Did I miss a memo somewhere about this?