@Neoito
This seems to be working fine in test account. Refer the attachment. Can you please share the screenshot of the salary structure with base amount.
Please have in mind that there are edits to the actual values of Salaries, the actual ones have been in conjunction with the Salary components and Formulae.
As replied this is working fine in the test account. Which version you are on? Also can you try creating a fresh test salary structure and see if the issue is replicating.