Hello Sarah M,
Welcome to the Community page,
Can you first clear the apps cache files. Doing this helps in fixing any sort of errors in the system. Here's how to do that:
1. Click the Help menu at the top of the screen.
2. Select the Rest App Data option on the drop-down section.
If you get the same result, uninstall and reinstall the Quickbooks Online app. This is to ensure you get the most recent version of the application.