lost link of left-top icon to top page on smartphone

I’m creating my team’s site using of bizlight pro, and I’m testing the site some devices.

If using with PC, it is working correctly, but if using with smartphone in portrait mode, tapping the top left icon does not take you to the top page.

What I want to do is to go to the top page when I press the top left icon in any state.

Please help me.
Thank you.