What does the circle in Xiaomi's mobile phone notification bar mean?

This icon indicates that the mobile phone has turned on "Traffic Saving Mode". When this mode is turned on, an icon with a double-headed arrow in the circle will appear in the notification bar. If you want to turn off the traffic saving mode, you can follow these steps:

Materials required: EMUI9. 1 system demonstration (this version of the traffic saving mode is called "intelligent traffic saving").

First turn on the phone and click the "Settings" icon on the phone desktop.

2. After entering the settings, click the first item "Wireless and Network" (the icon of traffic saving mode is in the upper right corner of the figure below, and the two-way arrow goes up and down).

3. In the wireless and network interface, click "Traffic Management".

4. Find "Intelligent Traffic Saving" or "Traffic Saving Mode" (with different names according to different system versions) in this interface, and click Open.

5. After turning on Smart Power Saving, click to turn off the Smart Power Saving switch.

6. When this function is turned off, the traffic mode icon saved in the notification bar disappears.