finally GOOD news :) - APPLE has sent an Xmas gift

as advised by beta tester Angelo Wiel in reply to my last update (thanks a lot mate!), the bug was finally eliminated by Apple in their latest public beta update iOS 11.2.5. So now it is only a matter of time until that update will be officially released for all users. If you don't have patience to wait you will need to register for the Apple public beta program here: https://beta.apple.com Afterwards you should perform an iTunes backup of your iPhone and archive(!) that backup as described here https://support.apple.com/en-us/HT203282 If you just make a backup with iTunes or iCloud but don't archive it it will be overwritten with any next iOS update of your beta state and you won't be able to restore your original backup in case you like to leave the Apple beta program later. Once you made the backup go to beta.apple.com/profile from your iOS device(!), to download the configuration profile. After login on that website your iOS device will prompt you to install it. Follow the onscreen instructions to allow installation. Once ready you will need to restart your iPhone. After restart go to software update in settings and search for new updates. The iOS Beta 11.2.5 will be offered to you for installation. When done you should see contact names on calls and messages again. I just did the installation myself and I am happy to confirm IT WORKS! So right in time for Xmas you will see again who's callin'. Merry Christmas to all of you.