Apologies, I should have better analyzed the problem before asking for help.
The problem indeed not the boolean toggle, but something related to the offset algorithm in this definition.
error_offset.gh (9.9 KB)
The shapediver model should show 2 rectangles, instead the offset is missing.
Everything works fine in Rhino/GH
I think I can use a work around, but I’d like to understand what’s wrong with this for learning purpose.
Thank you for your help