My coworkers and I share an excel file that we all edit at different times. Although we are editing at different times, we frequently notice that one person's changes are not saved. We are using the desktop application. In addition, sometimes the syncing is off and we do not get notified if another person is working. For example, my boss could be working at 12pm, but I would not be notified that he was editing the file at that time. Please advise!