When APPs run in the background for an extended period, they will be removed, causing the device to disconnect from the Mi Fitness APP and preventing data synchronization. To sync data, you need to enter the Mi Fitness APP for automatic reconnection and data synchronization. After the APP is removed in the background, reopening it will automatically reconnect the Xiaomi Smart Band 9 for normal synchronization.
The occurrence of being removed in the background is primarily due to the APP using up the RAM. To free up sufficient resources for newly opened APPs, the system needs to terminate some background-running APPs to free up RAM. The frequency of being removed in the background varies depending on the device model and iOS software version. For example, on an iPhone 12 with 4GB of RAM, running 4 apps will lead to being removed in the background on iOS 16.3.1. However, on the iOS 16.4 official version, running 5-6 APPs does not lead to being removed in the background. This varies depending on specific APPs, such as the camera APP which consumes relatively more memory.