Try this. Select the figures hip. Create a magnet (from the menu bar, Object > Create Magnet). Copy the text of the pose file below, and paste it into a text editor (Notepad will do). Save it to a pose folder as "CrotchFix.pz2". This will set the magnet the same way as was used in the image in my last post. If you wanted you could spawn a morph from the magnet, then delete the magnet from the figure. But a magnet is more flexible than a morph, so you may prefer to lock and hide the magnet, then save the figure back to the pallet with the magnet attached. The magnet is only  for when the lags are spread, in normal poses turn the "Mag 1" dial in the hip to zero. Here is the pose for the magnet:

{
//CrotchFix.pz2
version
        {
        number 4.01
        }

baseProp Mag Base 1:2
        {
        channels
                {
                rotateY yRotate
                        {
                        keys
                                {
                                k  0  0
                                }
                        }
                rotateX xRotate
                        {
                        keys
                                {
                                k  0  0
                                }
                        }
                rotateZ zRotate
                        {
                        keys
                                {
                                k  0  0
                                }
                        }
                translateX xTran
                        {
                        keys
                                {
                                k  0  0
                                }
                        }
                translateY yTran
                        {
                        keys
                                {
                                k  0  0.323642
                                }
                        }
                translateZ zTran
                        {
                        keys
                                {
                                k  0  -0.0101435
                                }
                        }
                }
        deformerProp Mag  1:2
        }

magnetDeformerProp Mag  1:2
        {
        channels
                {
                rotateY yRotate
                        {
                        keys
                                {
                                k  0  0
                                }
                        }
                rotateX xRotate
                        {
                        keys
                                {
                                k  0  0
                                }
                        }
                rotateZ zRotate
                        {
                        keys
                                {
                                k  0  0
                                }
                        }
                translateX xTran
                        {
                        keys
                                {
                                k  0  0
                                }
                        }
                translateY yTran
                        {
                        keys
                                {
                                k  0  0.606
                                }
                        }
                translateZ zTran
                        {
                        keys
                                {
                                k  0  0
                                }
                        }
                }
        }

sphereZoneProp Mag Zone 1:2
        {
        channels
                {
                rotateY yRotate
                        {
                        keys
                                {
                                k  0  0
                                }
                        }
                rotateX xRotate
                        {
                        keys
                                {
                                k  0  -0.00105191
                                }
                        }
                rotateZ zRotate
                        {
                        keys
                                {
                                k  0  -0.771484
                                }
                        }
                translateX xTran
                        {
                        keys
                                {
                                k  0  0
                                }
                        }
                translateY yTran
                        {
                        keys
                                {
                                k  0  0.326835
                                }
                        }
                translateZ zTran
                        {
                        keys
                                {
                                k  0  -0.0101435
                                }
                        }
                }
        buildSphere
        newFalloffCurve
        falloffCpt 0 1
        falloffCpt 0.2 0.93
        falloffCpt 0.8 0.07
        falloffCpt 1 0
        endFalloffCurve
        }

figure 
        {
        }
}