Poll thread does not stop when I change page

I am using vaadin 7 portlets inside Liferay 7. My structure is the following

  • liferayPage1 - UI1 - view1
  • liferayPage2 - UI2 - view2

a pollThread is run inside view1 and stops at the detach() event.

Unfortunately when i switch from page1 to page2, the detach() event of view1 is not fired and thus the thread keeps working.

What am I doing wrong?
Thank you