Hi Jiechong,
Sorry for the inconvenience it may have caused.
By default, the content and edits in PowerPoint presentations will not disappear automatically, unless it was edited by others or failure to save the file correctly results in loss of file content
I would like to confirm with you whether you’ve shared the presentation with other users. If so, the file may be modified by other users.
And if you turned on AutoSave or saved the presentation to OneDrive, you may find the historical versions of the file saved correctly and roll back to any version at any time. See
What is AutoSave? If you have not turned on AutoSave, I sincerely suggest you enable this feature to prevent similar problems in the future.
Besides, we would like to collect some information to further check it:
- Which version of Office do you have? After starting PowerPoint, click on
File > Account, please take a screenshot of the Product Information part and share it with us.
- Whether it was the first time the issue occurred? Have you encountered similar problems in other presentations?
Appreciate your understanding.
Best regards,
Madoc