We strongly recommend that you do not change the synchronization mode of a project as it may result in the loss of data. Carefully consider the synchronization mode of a project before creating it.
Data can be lost when changing the synchronization mode in the following ways:
Active Loss occurs when data that was synchronized in the previous mode is not synchronized in the new mode. This data could be lost or overwritten. Tracking information is most susceptible to active loss.
Passive Loss occurs when synchronization does not happen immediately before a synchronization mode change occurs. In this case, data that was entered since the last synchronization may be overwritten or discarded during synchronization in the new mode.
To change the synchronization mode, update the Integration Mode section in the project-level settings.
For additional information, see Changing Synchronization Modes and the Project Calendar.