While using my app, I have no invoices and my customer list is gone as well

Good morning, info-horizonlawn

Thanks for reaching out to the Community for support. I'd be happy to guide you in the right direction.

Sometimes browsing data accumulates and prevents the software from doing what it's supposed to do. I recommend trying these troubleshooting steps to see if it helps resolve the issue.

1. In the app, try to reset data by selecting “Menu” ☰ and tap Help & Feedback. Tap Refresh Data.
2. Restart or try another device
3. You can try uninstalling and reinstalling the QuickBooks Online app.
 

If the problem persists after trying the steps above, I recommend contacting the support team outside of the community. They have the appropriate tools to escalate the situation if they deem it necessary. You can contact them by following these steps:

Schedule a Callback: click (?)Help in the upper right > type and enter "Contact support" into the QB Assistant > click Contact Us > explain your situation > click Let's Talk > choose Get a callback.

You can also check the Get help with QuickBooks products and services article for the support hours.

Feel free to reach back out if you have any other questions.