Hi there, Kim.
I'm glad you reached out. Possible reason for encountering an error while syncing data could be due to cached data being stored.
To fix this, we can perform troubleshooting steps to refresh data into its default state.
Here's how:
- Open Settings.
- Select Apps or Apps & notifications.
- Find and tap QuickBooks Online (QBO).
- Tap Storage or Storage & Cache, then select Clear Data (or Clear Storage).
- Confirm if prompted.
Once done, restart your device and reopen your QBO mobile app to check if you can see customers and create invoices.
In the meantime, you can use incognito mode to have a clean slate. If issue persists, you can utilize other supported browser.
If you have any further questions, don't hesitate to let us know, we're here to help.