When can a @ViewScoped bean update its instance?

Question

Java

There is a @ViewScoped bean that contains some data. I update this bean via setInterval which calls the bean's method via AJAX (h:commandScript). The fields are updated on click, but after the interval is completed, i.e. The next call to the bean method, in the getters, the instance is changed to the old one and the values ​​set earlier are reset. Those. it turns out that the bean has two instances for the page. One before the interval, and the other after, which, subsequently, is reset to the previous one.
Any ideas why this might be happening?