A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data
It seems that you are experiencing a display issue with the Excel app on your iPhone, where the tab names are not visible until you rotate the screen. Unfortunately, the provided context does not contain specific information regarding display bugs in the Excel app for iOS or any troubleshooting steps for this particular issue.
For general display issues in Office applications, it is often recommended to ensure that your app is updated to the latest version and to check for any updates to your device's operating system. If the problem persists, you may want to reach out to Microsoft support for assistance specific to the Excel app on iOS.
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