Thanks for sharing this concern with us, @kstorrie.
I want to ensure that this payroll concern gets addressed properly.
There are several factors that affects the calculation of your payroll taxes, such as payroll type, employment allowance and how the reimbursement was recorded. To get this sorted out, I'd suggest getting in touch with our Customer Care Team. They can initiate a remote viewing session to verify what's causing the issue.
Please keep me in the loop if there's anything else you need with this concern. I'm just a post away to help you out. Take care!