[BUG]: `SimulationProperties.from_ini()` error

Describe the bug
When creating a SimulationProperties from an configuration file in the following way causes errors in binary evolution, stating that the binary variable is not a BinaryStar class instance.

To Reproduce

sim_prop = SimulationProperties.from_ini('1Zsun_binaries_params.ini', verbose=True)
sim_prop.load_steps()

star_1 = SingleStar(**{'mass': 31.616785, 'state': 'H-rich_Core_H_burning',
                'natal_kick_array':  [0, 4.190728383757787, 1.1521129697118118, 5.015343794234789]})
star_2 = SingleStar(**{'mass': 26.874267, 'state': 'H-rich_Core_H_burning',
                'natal_kick_array': [None, None, None, None]})
binary = BinaryStar(star_1, star_2, **{'time': 0.0,  'state': 'detached',  'event': 'ZAMS', 
                        'orbital_period':  501.99252706449792,'eccentricity': 0.0}, properties = sim_prop)

binary.evolve()

Start with SimulationProperties.from_ini() and load_steps(), then follow the constructed properties into BinaryStar.evolve() using the reproduction in the issue. Compare this path with directly constructed SimulationProperties and identify why the binary is rejected; done means the supplied example evolves without the BinaryStar class-instance error, with a regression test if the project has coverage for this path.