For this issue, please refer to the following troubleshooting methods:
1. Check whether there is enough storage space on the phone. If there is insufficient storage space, new contacts will not be saved;
2. Restart the phone and try again to check whether the issue is solved;
3. Please clear cache of the Contacts APP and try again;
4. Update the system to the latest version;
5. You can save contacts in Google Contacts, Xiaomi Account or your device;
6. Perform the factory reset after backup and try again.
If the all above methods are not effective, please submit your feedback in Settings.