Unable to edit off canvas menu | Astra theme, Spectra plugin

I have been using the Astra theme and Spectra plugin for my latest website project, and I am unable to edit the off-canvas menu. I am unable to understand where the menu is being managed. As you will see in the image attached, the off-canvas menu location is not selected but it is visible.

As a result, I am not able to edit the off-canvas menu. I tried to add the primary menu location for the off-canvas menu and the off-canvas menu promptly vanished! Pl help!

The page I need help with: [log in to see the link]