I have encountered a problem when drawing polygons from a icosahedral grid with a Mollweide projection only.

The same with a Robinson projection.

What do I miss ?

I have prepared a notebook with OPeNDAP access to the netcdf file that shows the problem.
https://thredds-su.ipsl.fr/thredds/fileServer/ipsl_thredds/brocksce/gridsCF/cartopy_bug_projection.html
https://thredds-su.ipsl.fr/thredds/fileServer/ipsl_thredds/brocksce/gridsCF/cartopy_bug_projection.ipynb

Tested with cartopy 0.20.2