The health code is black, indicating the personal information submitted by the user. The applied health code is under review, and normal colors can be displayed after review, such as green code, yellow code and red code.
Due to network and other reasons, the health code image cannot be refreshed in time. Open the network data, click the refresh button, and try to update the health code to get the normal color corresponding to the health code.
The user who applied for the health code failed authentication, and needed to retry authentication to get the normal health code.
Wechat health code is displayed in black. Maybe the user didn't have enough time to punch in or the health code was under review. The status of health code is to be released, or the system of health code has been updated. The device is not responding, so you can refresh it and try. It is also possible that the location service is not enabled.