Hi kyliem5-bigpond-,
You can create and lodge an earnings reset event if there's a need to remove an incorrect statement or reset the payroll reported via STP through QuickBooks Online. Please note each software has its own unique IDs and ways of reporting and you can't use one software to remove another software's STP report. If there's a need to reset event that was lodged through Xero, you can reach out to them for best assistance.
For more detailed information, you can check on these articles:
How to Lodge an STP reset event to fix incorrectly reported business or employee settings
The ATO is showing two income statements, how do I fix this?
Feel free to leave a comment below if you have any other questions.Have a nice day!