Thanks Pankaj. The reason why I'm exploring using the off-canvas menu instead of the main/horizontal menu is because of the nuisance of this template's scrolling (disappearing header/menu) feature, which might be great if one intends to use it, yet it's a HUGE hassle for anyone that doesn't.
After spending countless hours trying to fix a bug and almost giving up on the main/horizontal menu option, I recently noticed the bug only happens when someone uses the mousepad to move up or down (while using the keyboard arrow button works just fine).
Considering this is a very different problem/solution from the one described in this post's title, I created a new post to resolve my main problem.
https://www.joomlart.com/forums/d/39222-scrolling-with-mousepad-breaks-css-horizontal-menu-content
If I'm able to resolve this bug, I'll no longer want to use the Off-Canvas menu as described in this post.
Thanks anyway 🙂