Have checking it with our tech department that the lost hub problem you mentioned could be an error reported by the loss of transmitted data during automatic data synchronization. To avoid similar situation, modify the settings in the app, such as creating activity, etc.,  if there is a lost hub prompt, you can recover it via set--sync
And we will issue new firmware to optimise data synchronisation to avoid false positives soon, pls kindly help us wait patiently for it, tks