Menubar item doesn't close on another item click

Question

My issue is simple : When on a menubar with some items, when i open a menu i am not able to open another menu with one click. I have to first click to close the previous menu, then click to open the second menu. I have this issue with angular material menu component.

I have this issue for a while now and i have been reading lots and lots of stuff about this. Basically material shitty UX design consider the submenu opened as a pop-up, and gives it the focus.

I recently found this post here (look for the answer of FernandoJ) provided with this stackblitz here. This is EXACLTY what i want. But it's too good to be true i guess because when i import it as is in my project it doesn't work : The menu isn't opening in the first place. It may be because of this line in the app.module of the stackblitz :

bootstrap: [MenuOverviewExample],

And i dosen't use bootstrap. So i turn to you my fellow stackoverflowers, work your magic like you do so well all the times because it's starting to drive me crazy. please

If you have any question i'm happy to answer you, and also thank you very much !