Is it a manual base, the kind that has 2 bolts on the side of it and an engagement block? Or is it a fully programable base that moves with the shot pin on the turret cross slide?
If it is a manual base, the 2 bolts have to be fully loose to get the engagement block to rotate up into the turret cross slide. There is a cam inside the base that will not allow the engagement block to rotate if the bolts are not fully loose.
A programmable tailstock can be retaught by using Tailstock Joint Mode on the option panels.