Missing Data on online platform while collected in the field


Since the new update for humanitarian user on 01/03/2018, I faced an issue with my data for surveys already working and deployed for a long time. While collected in the field, some data are missing from the download. After some research I spotted that it was related to missing names or label for groups - any question within groups that were not names or labelled do not appear in the download, while it was working previously.

Following this, I changed all my surveys to correct this mistake and ensure having groups name and labels, however I can not recover the missing information for the transition period. Would you have any suggestion (except manual back up) to recover these information ?

Thanks a lot,