Donor mass against orbital period during evolution below the period gap. The magnetic field is assumed to appear on the WD surface when it is 2 Gyr old and the timescales for the detached phase triggered by the magnetic field appearance are given in the figure. The lower the donor mass when the magnetic field appears, the stronger the impact of the synchronizing torque, and consequently, the longer the detachment phase. For magnetic fields appearing around the period minimum or during the period bouncer evolution, the detachment phases last ≳1 Gyr.