To resolve this issue, let's take some troubleshooting steps to refresh your app data and eliminate any temporary glitches.
For Android devices:
Select the menu at the top right and choose Settings.
Press Refresh Data and choose Yes.
In your Phone Settings:
From your phone's settings, tap Apps (varies by device).
Choose the QuickBooks app from the list and select Storage.
Select Clear data.
After completing these steps, restart your device and reopen the QuickBooks Online (QBO) mobile app to check if the issue has been resolved.
If the problem continues, I recommend contacting our Intuit Experts directly. They can investigate this unusual behavior to ensure that you're able to upload your notes and attachments.