Hi. It doesn't activate, it just pops out. The reason for this is the code at 767px breakpoint.

.offcanvas-menu {
    width: 100%;
}

It looks like you made the change. The default is 300px. By the way, never change the main template files. Write all your code in to custom.css file.

In order to compensate for the 100% width use this code

body.ltr.offcanvs-position-right .offcanvas-menu {
    right: -100%;
}