Why does the T-1000 Terminator almost always go back to the same appearance of a policeman?
By often reusing the same face and body shape, it gives itself away. Sarah Connor and John Connor would learn to recognize that face and avoid it.
It could choose many other shapes and faces that Sarah and John never recognized. It saw, touched, or interacted with a bike gang member, employees at the steel foundry, other cops, a scientist, waitresses at the cafe, and a guard at the mental hospital. It could have used any of those. (Or maybe create a whole new face? Or mix and match features and clothes from different people it met.) Seems counter-productive to use the same face every time when it is tracking down Sarah and John at the steel foundry.
The out-of-universe explanation is that Robert Patrick played the villain and the producers wanted the same actor for most scenes in order to get a consistent acting style for the T-1000. Is there an in-universe explanation?