I am unable to add a product in my invoice. I am facing this issue in my one device only, if try to login in other device - it works well. I tried reinstalling app too.

I appreciate you for performing some steps to get this issue sorted out, @kailesh-rajdev.

I've got other troubleshooting steps that can help fix this hurdle so you can add a product to your invoice smoothly.

When utilizing QuickBooks Online on your device make sure that you have the latest version of the app. You may download the updates from the Google Play Store or Apple App Store. You may also follow the update steps below:

For Apple devices: 

1. Go to your Settings, then General.
2. Click on Software Update.

For Android devices: 

1. Go to your Settings, then About device.
2. Click on Update, then Check for Updates.
3. Choose Install.

You must be logged into QuickBooks Online mobile app as an administrator to access the settings.

However, if the problem continues, I recommend uninstalling and reinstalling the app. For more details about the things that you can do if you encounter performance issues with the app, please see this link: Learn how to solve common errors in QuickBooks Online mobile app.

If the same thing happens after following the steps, I suggest using a web browser in the meantime as a workaround.

Keep me posted how it goes or if you have any other questions.  Please know I’m only a post away if you need further assistance. Thanks for dropping by and take care!