I have gone through this and i am facing the same issue.
NOTE: The problem is when the Bahmni connect android tablet internet is disconnected
the observation form data of 1st form that has gone away from the left side panel and than when the app gets internet and we sync the data then the data only for two forms is saved and the rest data (data for the first form) is lost.
and when the internet is connected to Bahmni connect android tablet then also the 1st form goes away from the left side panel but at that time data is saved.