We have recently performed a magnetic neutron scattering study at WISH to understand the unusual metamagnetic behaviour of the Dirac semimetal candidate CeSbSe. Unexpectedly, the symmetry of its magnetic order pointed to the fact that the material is not tetragonal, as expected, but orthorhombic. In a HRPD express beamtime, we have now confirmed a 0.1% orthorhombic distortion in the ordered phase. We propose to complete this HRPD study by showing that this distortion ins not coupled to magnetism, but is already present at room temperature. Conversely, the sister compound CeSbTe was originally characterized as orthorhombic, while a more recent study at WISH based its findings of DIrac and Weyl semimetallic features on the assumption tetragonality. The proposed experiment will either disprove this, or confirm a surprisingly dissimilarity in symmetry (and hence topology) of these materials.