[AC Question]

Hello, everyone. I have a pretty strange issue.
I own a Sony Xperia SP phone and, the last three contacts that I have put in my phone do not show up on my contact screen at all, as if I never put them in my phone. But, when I check my call logs or messages sent to those numbers, their names show up completely normally. They are even existent in my Sync.ME application, but they aren't listed in my contacts application. This is pretty inconvenient because I'd like to delete old messages and calls so that they don't hog up my phone, but then those numbers will be lost.
Can you help me?