Why are some of my contacts being erased?

[AC Question]

Why are some of my contacts being erased ?

I'm having this problem that the phone number of certain contacts is being shown instead of their name, which my phone seems to have forgotten. And I can't add new contacts 'cause they disappeare too after a while (completely random amount of time). I've restarted my phone, but it didn't help. I have a Motorola Moto g 3 Android version.

 

[the tall guy]

Re: Why are some of my contacts being erased ?

Hi, do you know if the contacts are stored on the phone / sim or backed up to your Google account?