Bug? Boolean Union

An oddity I saved. There are two closed polysurfaces in this file that don’t appear to have any errors. If I try to boolean union, one of the polysurfaces simply disappears.
Problem Union 5.3dm.zip (148.6 KB)

Hello- a thing to just keep in mind - coincident faces, apart from planar ones, generally do not mix well with Boolean operations in Rhino. It is a limitation, or a bug, but there it is, there is no way around it other than to revert to dealing with surfaces and just trim that thing in.


I just thought I’d share in case it might help.