Hi @Jarvis, Kyle ,
Welcome to Q&A forum!
Please try to remove hidden data and personal information by inspecting documents, presentations, or workbooks before sharing files with other users.
Besides, since this is a known issue for earlier versions of Office.
If the methods in the official KB does not work for Office 365, I suggest you refer to this link to submit a feedback to Microsoft directly.
Thanks for your understanding~
If an Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.