Antenna ground and digital ground
From my knowledge, ground splits are detrimental in 90% of cases. One reason could be that our brain's EM simulator can never be quite perfect. That often leads to GND cuts where they cause havoc. So I always sway on the conservative side and make my grounds as solid as possible. In your case keeping ground currents from AGND by splits probably makes sense, considering your first iteration experience. But keep in mind that signals should not cross any of these splits.
What I would stay away from is splitting the antenna ground from DGND. Keep in mind that RF always works relative to a ground mass. When you reduce it, you reduce the transmitted efficiency. This counts especially in the vicinity of the antenna.
Anyway, is this an off the shelf module? If so, don't they mention the correct usage in the datasheet?