Simply polygon offset not working to the inner direction

Hi guys,

I haven’t notice it before but the simple polygon offset to the inner direction gives an error after updating Rhino.

I’ve tested with some plugins mentioned in the forum such as Fennec, Pufferfish, and Clipper, but it all fail at certain distance, -6 in particular.

Interestingly it works well when I bake the geometry and offset with the same distance.

I assume this might be a potential bug since my initial code wasn’t giving an error before update and the rhino offset is working okay.

I’d appreciate if anyone help on this issue.
Thank you. (13.0 KB)

Rhino version: