Hello Julio,
Treasury and Risk Management-Transaction Manager-General Settings-Accounting-Settings for Position Management-Set the Effects of the Update Types on the Position Components
The standard assign position change category is 1010 in system you should change the same to 1015
Please note, incase this situation is applicable to few product, I would recommend you to create new update type for your product and work, Because once change this it will apply for all the product where interest is coming into picture.
Let me know if you need any futher inputs.
Regards,
Jain