Different tax codes on payslip and self assessment

Hi, I have the same tax code (1718L) on my payslip, P60 and Personal tax account. However when I complete self assessment, the calculation reverts to the tax code (1257L) leading to additional 000s in tax charges. I thought this was a mistake when it first occurred last year while completing 2022/23 return, but it has repeated when trying to do return for 2023/24. Can someone explain and direct me on what to do please? Thank you

Hi,
Unfortunately, it is not possible to review personal matters in this forum. 
For individualised assistance please contact our self assessment helpline or contact our webchat:  
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Thank you