You need to figure out why it is not adding the overtime hours.

let vDate := Date;
let vStaff := Staff;
let vBefore := sum((select Carga_Horas)[Date <= vDate and Staff = vStaff].Hours);
let dBefore := sum((select Carga_Horas)[Date >= vDate and Staff = vStaff].Overtime);
let result := vBefore + dBefore;
styled(text(result), if text(result) < 0 then "red" else "green" end, "")

The filters in line 3 and 4 do not look the same.