The [Out of Range] message appears on the Xiaomi 4K Monitor A27Ui because the resolution setting is incorrect.
To fix this issue, please refer to the following steps:
Disconnect the Xiaomi monitor from your computer or video output device;
Connect your computer to a different monitor that can display the current output settings;
On your computer, open the display settings and reduce the resolution and refresh rate. The recommended setting is 3840 × 2160 resolution at 60 Hz refresh rate;
Once the resolution and refresh rate have been adjusted, reconnect the Xiaomi 4K Monitor A27Ui;
If the above steps do not resolve the issue, please contact after-sales service for further assistance and professional inspection. A repair will be necessary in this case.