The Xiaomi 15 Ultra comes with a built-in Xiaomi Cast feature and supports the Wi-Fi Display (Miracast) protocol.
To fix the Xiaomi 15 Ultra cast screen problem, please refer to the following steps:
1. Make sure the phone and the TV or receiving device are connected to the same Wi-Fi network, and place them close to the router to minimize interference;
2. If you are unable to connect to the receiving device, check the local network and enable Wireless Display Certification in Developer Options;
3. If the casting function fails to start or is unresponsive, update the firmware of your Xiaomi TV or box and make sure it supports Miracast casting;
4. If there are software or system issues, try updating your phone’s system, restarting the device, or resetting network settings;
5. If the problem persists, contact official service centers for further inspection.