Why is my Impulse theme mega menu not functioning properly?

Hi All -

Working on a client’s website in the Impulse theme to make a mega menu - I have made these in the past and know that to get it going, you need to have 3 levels. I have done that, plus checked the box to allow for mega menu in the theme, it’s still not working, but my concern is that there is custom code in there, that maybe somehow blocking it. Could someone help? I am using it in an unpublished theme.

Thanks!