Recently, I had an activity (walking, > 90 km, > 18h). Since the battery life is quite limited, I charged the watch during almost every break from Xiaomi powerbank PLM02ZM. However, after the 9th break, I noticed that the watch screen looked like it was connected to a computer in mass storage mode. After disconnecting, I had realized that the activity is stopped and I cannot continue it.
Do you have any idea why this has happened? What can I do to prevent it the next time?