The initial stage of Ultra Relativistic Heavy Ion Collisions is dominated by low Bjorken-x degrees of freedom, which can be understood as a classical color field, obeying Classical Yang-Mills (CYM) equations. Such a phase, occurring in the first fractions of a fm/c after the collision and leading towards an equilibrated quark-gluon plasma, is called the Glasma, and the CYM equations can be studied both analytically (e.g. by employing a small time expansion) or numerically. However, such a success of the glasma simulation has been largely limited by the boost invariance assumption, which shows good agreement with experimental data only around the midrapidity region. Recently, much attention has been paid to the 3 + 1-dimensional glasma simulations, which aim to go beyond the boost invariance assumption, as necessary to understand observables across a broader region of rapidity. We will first discuss the behaviour of such a non boost-invariant Glasma in high energy p-A collisions, in which we implement a more realistic initial state condition than the usual ones from studies on A-A. After that, we study the propagation of Heavy Quarks in this medium, which are well-known phenomenological probes of such a phase.