iPhone – The labels in the addresses and phone numbers return to the home page

I am using iOS 12.1 on an iPhone 6.

Sometimes (not always) when you label an address or phone number with one of the standard labels or a custom label, it appears on the screen, but after saving the contact, it returns to Home.

I tried to close the application; I tried to restart my phone, but it still does not work (for that contact).

Any ideas?