Gromacs 2023.1 never updates *_prev.cpt checkpoint file
It seems that Gromacs 2023.1 never replaces *_prev.cpt checkpoint file with the newer one if there already exist a *_prev.cpt file. It writes a *_prev.cpt only if there is no one already existing, and then never updates it.
For this reason, if you restart your simulation from the previous checkpoint file (*_prev.cpt), you restart it from the very first one and lose the whole trajectory.