Hi everyone,
I think I have found a way to activate this error.
At least it works every time I do it on my iPhone 6, iOS 11.0.3
Network carrier: PLUS GSM, I am in Poland.
Please follow this instruction and check:
1. go to Settings-Phone-Show My Caller ID, and switch it on
2. make a test call and make sure your number is visible.
3. go to Settings-Carrier and switch off automatic network selection
4. wait until all networks will be visible and choose one of your NON home networks (the one you can not log in to)
5. wait until you see in the upper left corner "No Service"
6. now go back and chose manually your home network
7. in upper left corner you should see again your carrier network logo
8. now make another test call... and BOOM! "Private no." calling
9. go to Settings-Phone-Show My Caller ID (just check, it should be on), and your number will be visible again
Now who and how fast can finally fix this?!