SliderPanel - Not staying collapsed using push

Hello,

I use the SliderPanel addon in my project ( https://vaadin.com/directory#!addon/sliderpanel ) as some kind of sidebar navigation.

I am in a situation where I need to show a spinner in the UI.
By consequence I manualy push that change to the UI by uing 

UI.getCurrent().push();

The cause I need to do this is that before I navigate to a view I want to show a spinner as some views could contain heavy computations before they are finished to show.

Unfortunately, if i collapse the SliderPanel and show the spinner using push, the SilderPanel gets visible again after the view is visible.

Is there someone that could help me out?

I attached a minimum example of what I mean (just change the vies using the SliderPanel).