Search:

I'm kinda wondering how a Shapton can be "around 8k" :)

I'm suggesting the scope at the end not just at bevel set. You don't use the TNT at 8k do you ?
At worse you can send it out to someone for an assessment & /or fix. Some times a different...

So the other extreme is you may have a bit of a wire edge.
Sometimes looking at the edge under magnification can give you an idea on what's happening.

I'd more likely suspect the bevel than the end game but not seeing the razor that's just a WAG.