On Confluence Cloud, when an user click on the save button, nothing seems to happen. After several seconds, a flag is displayed confirming the save.
Since we doesn't control the top-right close button, if the user exit the Elements Spreadsheet editor before the confirmation flag, all his changes are lost.
We must add a flag with the a message like :
Saving document, please do not close the editor now...
just after the save action. Once the save is done, the flag is replaced by the save confirmation flag.