I have a galaxy s8 plus. When I receive incoming calls from a contact in my phone book only their number displays. But when I go in my recent calls both their name and number is there. Like most people I don't know everyone's phone number so when people are calling me, I don't know who they are until after I miss it. I've already tried restarting my phone. No luck And I checked for a software update. It's up to date.
