SendGrid renders nothing when the template has "each" in "greaterThan"

Question

I have a SendGrid's dynamic template with "each" in "greaterThan" like this:

{{#greaterThan (length users) 0}}
    <p>not empty</p>
    {{#each users}}
        <p>{{this.name}}</p>
    {{/each}}
{{/greaterThan}}

Expected behavior is that I get:

<p>not empty</p>
<p>name1</p>
<p>name2</p>

but I get:

<p>not empty</p>

Why is the "each" block dropped?