Negative Surface Extension script in Grasshopper not working

Hi!

I’m trying to implement a script to make some surfaces smaller.
I use the following python script within a Py3 component, where srf is the input surface:

import Rhino as rc
a = srf.Extend(rc.Geometry.IsoStatus.North, -1, False)

Negative values (in this case -1) do not work, positive ones do. I know it was a problem in v7, but I thought it was fixed. I’m using Rhino 8, latest official update on the mac.

Also tried various other scripts from other users including c# of which I don’t understand much :wink:

Can you help?
Kind regards

Sebastian