In iOS 14.7.1 and above app disconnecting from BLE device when writing data in a particular characteristic

While writing data in BLE device connection loss happened in between BLE device and application (file size is 459 KB, the file type is .bin). It's happened particularly in iOS 14.7.1 and above. iOS 14.6 and before iOS, it will work fine.

It observes that MTU size is also different in iOS 14.4 and iOS 14.7.

When disconnection happened CoreBluetooth -> centralManager: didDisconnectPeripheral delegate method call.

Divide bin file data into 1024 chunk sizes and write data into BLE device as per receive MTU size (MTU - 3)

Is any string that needs to add for iOS 14.7 and above or what should I needs to check.