Please check processing cls 62 and specifications for your IT0008 wage types. I feel It's referring in following way.
This might be causing error.
However, you need to check the payroll log in below path what is the input, processing & output tables for ZA22 then can be able to trace the issue.
Process additional payments/deductions > SI applicable earnings cummulation > ELSE > ZA22
If you change specfici to blank or 2 you won't come across any issues. I am not sure what is your business requirement.
Let me know any queries.
Thanks,
Hafeez.