Most of my miles from September 2023 are missing from Quickbooks?

Hi nickthedogtrainer, thanks for reaching out to the Community

We're not aware of any current issues with missing mileage data in QuickBooks Self-Employed. Do you experience the same issue when viewing the mileage on both the app and web? 

Additionally, please try exporting all trips (from the web, navigate to Reports > Mileage log > Set time range to All time > Click the drop-down beside View > Download to see if the trips show there.