Unable To Clone LI Element Inside Template

I have:

<template id="tmpl">
    <li>
        <a href="#">Link</a>
    </li>
</template>

const tmpl = document.getElementById("tmpl");

const cloned = tmpl.content.cloneNode(true);   // doesn't work

tmpl.content doesn’t work if the first element is a li element.

Problem:

I cannot clone the template child like ie:tmpl.content.cloneNode(true)

Expectation:

const cloned = tmpl.content.cloneNode(true)

returns

<li>
    <a href="#">Link</a>
</li>

Why is this happening?