Discrepancy of £26k between HMRC app and March payslip YTD

My March Payslip for 2026 shows ~£197k of taxable income, HMRC app says ~£171k. Income is a combination of salary, bonus, and RSUs.

I'm waiting for my P60 and P11D before doing my SA, but not sure where to query this difference? Would you go to payroll first?