Hi @Anonymous,
I have made a test on my side, and don't have the issue that you mentioned.
Please check if you have format your Excel file data as a Table on your side.
Please also check if the connection to the Excel table within your app is invalid. Please consider remove the connection from your app, and then re-add a new connection to your Excel table, then check if the data is displayed well within your app.
In addition, please also take a try to clear cache of your browser, then check if the issue still exists.
If the issue still exists, please consider submit an assisted support ticket through the following link:
https://powerapps.microsoft.com/en-us/support/pro/
Best regards,
Kris