Why does the upgrade time of the device take so long？/ What should I do if my device keeps showing up during the upgrade process?

Please upgrade the APP to the latest version. Make sure that the battery level of the device is greater than 50% and the remaining memory of the SD( SD card memory is greater than 8GB and not more than 64GB) is more than 5%. Then try to reset the device. 

If the upgrade has not been completed after 24 hours, please contact customer service support with the following information:
1. IMEI Code
2. The status of the indicators (SD, Signal, and Account) in setup mode