Caller Id showing unkown caller instead of phone number

My s6 is stock rooted running 5.1.1 and it used to show the phone number anytime i got a call from someone not in my contacts list but last week it started just showing unknown caller. The caller's phone numbers show up on the call logs, but not on the call screen. I haven't changed any of the settings recently or installed or even updated any apps. I checked all over but I can't find anything on how to change it back.