JavaScript - Depois de horas tentando resolver sozinho, por favor me ajudem

Estava estudando JavaScript com alguns tutoriais de navbar responsivas com HTML e CSS, até me deparar com esse erro!!

Uncaught TypeError: Cannot read properties of undefined (reading 'navList') at handleClick

    class MobileNavbar {
        constructor(mobileMenu, navList, navLinks) {
            this.mobileMenu = document.querySelector(mobileMenu);
            this.navList = document.querySelector(navList);
            this.navLinks = document.querySelector(navLinks);
            this.activeClass = "active";
    
            this.handleClick = this.handleClick.bind();
        }

        handleClick() {
            console.log(this);
            this.navList.classList.toggle(this.activeClass);
        }

        addClickEvent() {
            this.mobileMenu.addEventListener("click", this.handleClick);
        }

        init() {
            if (this.mobileMenu) {
                this.addClickEvent()
            }
            return this;
        }
    }

    const mobileNavbar = new MobileNavbar(
        ".mobile-menu",
        ".nav-list",
        ".nav-list li",
    );
    mobileNavbar.init();