Trouble setting root from side menu after setting root on some page


I am having trouble navigating from side menu to a page that I previously set root on. After a successful operation on a page I call function setRoot() and navigate to another page. Every page contains side Menu that is a part of main app.html file. After I navigate to that other page and try to setRoot() to that page I was previously on nothing happens. If I set any other page as root everything starts working again. Here is a code:

A method called upon successful operation on a page.

Methods in an app.component.ts file for buttons in menu (the bordered one doesnt work after successful operation):

I hope anyone can help. Thank you in beforehand.