I noted the issue of phone calls, SMS & MMS messages starting to come in with phone numbers only and not resolving to contacts. Even thought the contacts already had the number in their profile.
I worked with Apple support and my issue seemed to be specific to Verizon. I corrected the issue by call *228 and use option #1 to program your phone again.
The fix was not immediate and after 3-5 minutes my phone numbers in recent calls did indeed resolve to a name versus just displaying the number. I also noted the SMS/MMS messages did not truncate or combine, though new messages did resolve to a name.