Oh! Well if you, a seasoned Blender contributor, have already found it to be a Blender bug, then it explains why I couldn’t see any misfit prop in the UI for that piece of geometry…
When I have time, I’ll should check if it’s already been reported, otherwise I’d try and recreate the problem from an empty scene to report it, it would force me to learn a few things about grease pencil.
Thanks for the answer!
