Hi @lok-chan-time-ms.

In your case, I suggest contacting HMRC Support since the May payroll was created through Payee Tools. They have the resources to remove the double counted May payroll.

I'm also adding this article for future reference: Import Employees from HMRC Basic Tools in QuickBooks Online Payroll (UK).

I want to make sure everything is taken care of for you, so please let me know if you have any other issues or concerns. I'll be here to help. Have a good one!