If the Xiaomi Outdoor Camera CW100 Dual has an issue that there is an anomaly with the microSD card, please refer to the following suggestions:
Use a high-speed FAT32-format microSD card designed specifically for dash cams or cameras, and ensure it’s from a reputable manufacturer;
Confirm that a compatible microSD card is properly installed in the camera, as the device cannot store recordings or playback historical videos without one;
If the microSD card is not recording or cannot automatically overwrite old files, try formatting it through the storage settings in the Xiaomi Home App;
If formatting via the App is unsuccessful, you can use a card reader to format the microSD card on a computer. After formatting, power off the camera, reinsert the microSD card, and restart the camera.
Note:
Formatting will delete all files on the microSD card.