  Effective models of gravitational collapse in loop quantum gravity for the
Lema\^itre-Tolman-Bondi spacetime predict that collapsing matter reaches a
maximum finite density, bounces, and then expands outwards. We show that in the
marginally bound case, shell-crossing singularities commonly occur for
inhomogeneous initial profiles of the dust energy density; this is the case in
particular for all profiles that are continuous and of compact support,
including configurations arbitrarily close to the Oppenheimer-Snyder model.
When a shell-crossing singularity occurs, it is necessary to seek weak
solutions to the dynamics; we argue that weak solutions typically contain shock
waves.
