Remarkable "Bevel" Behaviour

Check the images.
I don’t have any idea why it’s beveling inward like this, I’m used to it smoothing off edges… not this. :no:
That being said, it’s kinda cool, and might be worth adding into the bevel tool? ( Let’s say if you specificy negative edges , so that you can scroll down to bevek inward, and scroll up to bevel outward ),

Anyhoe, does anybody know what causes this?

The bevel profile setting is < 0.5