If the system OTA updates on the Xiaomi Watch 5 stall at 99% or 100%, please refer to the following troubleshooting steps:
1. When the update progress reaches 99% or 100%, the watch can still be downloading the update file and verifying its integrity, which can cause the progress to appear stuck. The verification process takes no more than one to two minutes, depending on the network speed.
2. An unstable or slow network connection will cause the verification or download process to take longer, which will result in the update progress not changing for a period of time. Please check whether the watch is connected to a stable network and try reconnecting if necessary.
3. If the update process remains stuck for an extended period, the system can not be able to continue the update. Please press and hold the power button (side button) for about 12 seconds to force a restart, and then try updating again.
4. If the issue persists, please contact the after-sales service for further inspection.