After doing a firmware update, my log file no longer synchronizes, and my first five hours have disappeared. I tried clearing the records and syncing again, and another hour disappeared. I don't see how to access through my online account, is there a fix for this? No other topics show up here but a Google search indicates I am not alone, but can't find an answer.

On your tablet app go to the ME icon then DJI Forum and log in there.  The login may carry forward to all the other icons including the flight record.

Hi ,Tim
Sorry to have brought you into trouble .Would you please post a video of that  ?