When the SUN2000 inverter loses connection with the monitoring portal for a longer period, manual data recovery is required.
Steps:
1) Connect with your (installer) account on FusionSolar at https://intl.fusionsolar.huawei.com
2) Go to Settings > Data amendament

3) Data Recovery > Create

4) Enter data recovery details and press OK

Note:
Data recovery for extended periods of time (30 days) can take up to 1h.