Issue with no axis appearing for contour projections of moll and robin

The following code is supposed to produce a moll contour projection, it is successful however no axis appear. The same occurs with robin as the proj.

f=cf.read("~/cfplot_data/ggap.nc")[0]
cfp.gopen(file="projections1.png")
cfp.mapset(proj="moll")
cfp.con(f.subspace(pressure=850), lines=False, title = "moll", colorbar_position=[0.1, 0.1, 0.8, 0.02], colorbar_orientation='horizontal')
cfp.gclose()

Example with moll

Example with robin

Environment

Using the main branch:

>>> cf.environment()
Platform: Linux-5.4.0-131-generic-x86_64-with-glibc2.31 
HDF5 library: 1.14.3 
netcdf library: 4.9.2 
udunits2 library: /home/natalia/cfplot_data/.conda/lib/libudunits2.so.0 
esmpy/ESMF: 8.6.1 /home/natalia/cfplot_data/.conda/lib/python3.10/site-packages/esmpy/__init__.py
Python: 3.10.14 /home/natalia/cfplot_data/.conda/bin/python
dask: 2024.7.1 /home/natalia/cfplot_data/.conda/lib/python3.10/site-packages/dask/__init__.py
netCDF4: 1.6.5 /home/natalia/cfplot_data/.conda/lib/python3.10/site-packages/netCDF4/__init__.py
psutil: 6.0.0 /home/natalia/cfplot_data/.conda/lib/python3.10/site-packages/psutil/__init__.py
packaging: 24.1 /home/natalia/cfplot_data/.conda/lib/python3.10/site-packages/packaging/__init__.py
numpy: 2.0.1 /home/natalia/cfplot_data/.conda/lib/python3.10/site-packages/numpy/__init__.py
scipy: 1.14.0 /home/natalia/cfplot_data/.conda/lib/python3.10/site-packages/scipy/__init__.py
matplotlib: 3.9.1 /home/natalia/cfplot_data/.conda/lib/python3.10/site-packages/matplotlib/__init__.py
cftime: 1.6.4 /home/natalia/cfplot_data/.conda/lib/python3.10/site-packages/cftime/__init__.py
cfunits: 3.3.7 /home/natalia/cfplot_data/.conda/lib/python3.10/site-packages/cfunits/__init__.py
cfplot: 3.3.0 /home/natalia/cfplot_data/.conda/lib/python3.10/site-packages/cfplot/__init__.py
cfdm: 1.11.1.0 /home/natalia/cfplot_data/.conda/lib/python3.10/site-packages/cfdm/__init__.py
cf: 3.16.2 /home/natalia/cfplot_data/.conda/lib/python3.10/site-packages/cf/__init__.py

Start by running the reported Python example with cfp.gopen, cfp.mapset, and cfp.con for both moll and robin projections, using the supplied environment details. Trace the projection and axis-handling entry points until the missing axes are explained; done means both projection outputs display their expected axes without breaking the contour or colorbar.