It appears to stitch OK with Panoweaver 8 although not perfect.
The FOV is 88.70 (Fullframe Fisheye) at 10mm
I would say your NPP setting is out slightly. You are also not shooting the scene correctly. Your shutter speed, ISO, WB and Aperture should remain exactly the same for every shot. Your Aperture should be locked in at f/8 to f/11 as this is the sweet spot for this lens.
Anyway here is a stitched version to play with.
When I have a bit of time I will test the images with Panoweaver 6.0