This has been my thought. Usually when a woman goes missing the first person they suspect is the violent ex. I can't go into detail here but honestly more than once I have seen firsthand that TPS actually isn't quite sure how to handle violence in relationships between men, when it should be obvious that they ought to treat it the same as domestic violence situations between men and women.
......only IF it is domestic violence. There is non domestic violence as well. They have to follow whatever the laws and their investigation show.