Hello, good day and thanks for your question. Sorry to know and apologies about this as others are reporting of the same issue and there are a couple of workaround that you can try and you can also check the below links for reference. It is still recommended to report this as a feedback via the app or leave a review at the App Store for this to get checked and hopefully a new update will be released soon to patch this issue.
- Restart the device.
- Setting > General > App > Excel > Reset Excel > Enable all three options (Clear All Workbooks / Delete Sign-in Credentials / Reset Cloud Settings). This is temporary at the time being. https://www.reddit.com/r/excel/comments/1o9pvno/excel_on_ios_and_ipad_os_freezes_and_completely
- Close and uninstall then reinstall and open it again and it worked as per the below. https://www.reddit.com/r/excel/comments/1o9pvno/comment/nk4eqv7
https://learn.microsoft.com/en-us/answers/questions/5587312/word-keeps-freezing-on-ipad
Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information.