Firmware bug or ISP-enforced override (some ISPs like Vodafone or T-Mobile lock DNS on their branded MC888 Pro units). Fix: Check for firmware updates (Admin > Device Management > Firmware Update). If not fixed, use per-device DNS (Method 3). As a last resort, put the MC888 Pro in bridge mode and use a separate router with full DNS control.

To change the DNS settings ZTE MC888 Pro 5G router, follow these steps: Log in to the Web Interface

, this is typically or http://192.168.32.1 .