what you can do is add a click event to your ckeditor and assign below method and check what element class draggable=true is getting added. (Ck ediotr adds this attribute in dom)
restrictEvent() {
document.querySelectorAll(".parent-element-class
.element-class").forEach(element => {
element.addEventListener("dragstart", (event) => {
event.preventDefault();
event.stopPropagation();
console.log("drag started");
});
});
}