Hi @Parvathy,
Are you using SharePoint custom forms? Have you tried clear cache on IE or open it in an InPrivate mode?
To test this issue, I create a custom form on IE and it works fine without any issues.
Could you please clear cache then try again with it? If you are still having the issue, please feel free post back.
Besides, please post PowerApps related issues on PowerApps forum so that you could get the most qualified solutions for you issues. Thanks for your understanding.
Best regards,
Mabel Mao