I've run it through my entire arsenal of hones, tricks etc...
With and without slurry, pasted strops, sandpapers.

Under magnification, I can watch as that spot scratches faster and deeper than regular razor steel, it also polishes faster. It's almost like I'm trying to hone aluminum (yes I have tried)
I've seen Zeepks take and hold an edge better...

If I had to guess, I would assume they tried to spot temper the blade, and missed part of it, or they only dipped part of it?