Attribute doesn't refresh his value
I've created a process that iterates in a moment (please find attached the image), and when that happens, some attributes were supposed to refresh their values, but that isn't happening. At "Índices atuais (Especialista 1)", "Índices atuais (Especialista 2)" and "Índices atuais (Especialista 3)" I've set the value for the following attributes: SEV, OCC and DET. After that, at the task "Analisar índices" I've used these attributes to calculate the Average and the STANDARD DEVIATION. For that, I've wrote a expression for each one. I think that the problem isn't at the expressions, because at the first iteration, everything works perfectly. But at the second iteration, I change the values of the SEV, OCC and DET but the Average and STANDARD DEVIATION remains with the old value, the attribute doesn't recalculate the values after the iteration.
What should I do? I really need some help with this!
Please find attached the expressions.