Error IBAN calculation in BP (vendor) financial & accounting

Dear SAP,

I met an error when I create BP (vendor financial accounting role), when I put bank details with the correct information, the system calculates a wrong IBAN please see the example below:

IBAN: IT02K0307501603CC1510650172

Bank key: 0307501603

Bank Account: CC1510650172

Control Key: K

I don't know why the IBAN is calculate wrongs.

Could you please help me?

Thanks & Regards