in Quest Pro, left and right eyes are always exactly 65mm apart

We are using OVRPlugin.GetEyeGazesState in Unity to get left/right eye pose. 

In every frame, and for every person we tested, the distance between the left and right eye is always exactly 65mm.

Their actual distance between the eyes ranged from 60 to 71mm; we did Fit Adjustment and Eye Tracking Calibration: fit adjustment shows the correct distance between the eyes, and the eye calibration is successful. Still, the eye positions we get from OVREyeGaze are clearly not correct.

Does anyone know why is that, and how to get the actual eye positions?