Solid High Harmonic Generation (HHG) has seen a recent surge in interest, as a promising path for bright, compact, and tuneable XUV sources as well as a spectroscopic tool to understand ultrafast electron dynamics in solids. The high electron density renders solids a good candidate for HHG [1]. However, to optimise the efficiency for the HHG process, a thorough understanding of the electron motion between the conduction and valence bands is key, yet remains inconclusive [2]. Probing the electron potential to have access to the microscopic properties of the crystal is the first step to achieve this understanding [3]. It has been previously demonstrated that the spectral properties of HHG are strongly related to the crystal symmetry and geometry [4].