define_vessel_structure_settings does not create vessels starting from boundary

[RecurvedBow]

Describe the bug
Sometimes, if a vessel is created starting on a tissue boundary, the vessel does not assume a tube structure.

Specify a priority (low, medium, high)
medium

To Reproduce
Define a homogeneous tissue of size 16 x 16 x 10 mm, spacing = 0.5mm and define a single vessel with the following vessel dictionary:

vessel_dictionary = sp.define_vessel_structure_settings(vessel_start_mm=[10, 16, 0.2],
                                                            vessel_direction_mm=[-1, -1, 0.0],
                                                            molecular_composition=sp.TISSUE_LIBRARY.blood(0.7),
                                                            radius_mm=2.0,
                                                            curvature_factor=0.0,
                                                            radius_variation_factor=1.0,
                                                            bifurcation_length_mm=1000.0,
                                                            priority=5,
                                                            consider_partial_volume=True,
                                                            adhere_to_deformation=True)

Then run any MCX simulation and acquire the semantic map. Aggregate by the z-Dimension to get the vessel area viewed from above the tissue.

Current Behavior
The vessel only occupies a small area:

Expected behavior
With these parameters, the vessel should have a tube structure like this:

This image was created by changing the start position to [10, 15.99, 0.2].