Hi @chandni90 ,
Which version is your PowerApps Mobile App in your iOS device?
Which version is your iOS device?
Based on the issue that you mentioned, I have made a test, and don't have the issue that you mentioned. The version of PowerApps Mobile App is 3.19082.15, the version of my iPhone X is 12.4.
Please check if the version of your PowerApps Mobile App has been upgraded to the latest version, if not, please upgrade it to the latest version, then try your app again, check if the issue is solved.
Also please consider uninstall the PowerApps Mobile App from your iOS device, then re-install it again, try your app again, check if the issue is fixed..
Best regards,