Your mobile does not show you the name of your contacts when they call? This is usually an upgrade issue, but you can fix it temporarily with a couple of checks and a few changes to the settings.
To do this, start by opening the Phone app, go to Settings >> Other call settings and check that “Show info. Call ”is enabled. And on the other hand, another option that has worked for some users is to disable the "Caller ID and AntiSpam" function.
Although this function is essential so that calls from strangers do not become a nuisance, in some cases it has caused conflict in the identification of contacts. So try disabling it temporarily to see if it can work for you. It is not an ideal solution, but it may be useful until an update fixes the error.