https://qbo.intuit.com/app/apptransactions no longer provides access to transactions coming in from connected apps. A list of available apps is displayed ("Sync your sales channel data with QuickBooks") with suggestions to connect them, but they are already connected and just return to this screen. The apps still show up as connected at https://qbo.intuit.com/app/appcenter/myapps. Seems like a QBO update broke something.