A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
It sounds like you are experiencing issues with the Excel app on your Android device, specifically related to the loss of cell borders and deletion of cells. Unfortunately, the mobile versions of Office apps, including Excel, are known to be limited in functionality compared to their desktop counterparts. This could potentially lead to unexpected behavior, such as the issues you are encountering.
While it's unclear if this is a specific bug or a limitation of the mobile app, it is advisable to report this behavior through the feedback option within the app. Microsoft developers may not monitor forums, but user feedback can help them identify and address issues in future updates.
In the meantime, using the version history feature in OneDrive, as you mentioned, is a good way to recover lost data. If the problem persists, you might consider using the desktop version of Excel for more complex tasks until the mobile app improves.
References: