Hi,
Users are experiencing the same issue, and it seems that it was after the update to the Office apps in the App Store. I recommend reporting the issue using the in-app feedback option. Open the Excel app on your device, and go to Help > Feedback.
You may also try the solutions that solved this issue before, or temporary workarounds while waiting for the next update.
- Clear the cache and data of your app and restart afterward.
- Uninstall the app and then make sure to restart your device. Install the app on the App Store.
- Work offline by turning the Airplane mode on.
- Use Excel online and turn on desktop mode. After turning on, refresh.
- Check if you can access Excel on Outlook or OneDrive online. Make sure that you are on desktop mode.
If you require further assistance, please don't hesitate to let me know.
Stay Safe!