Confluence automation Smart Value won't give me a clickable URL in Teams

[Tracy B]

I set up a Confluence automation to sent a message to a MS Teams channel when a new blog post is published in a space. I'm using:

A new blog post titled '{{blogpost.title}}' has been published by {{blogpost.author.fullName}}.
Please review at {{blogpost.url}}

The message shows up in Microsoft Teams correctly, but when the URL is published, the link is not clickable. I'm trying to remove barriers to reading the blog posts, and this creates a new one. Why is the URL simply plain text when cutting and pasting the same thing into a message resolves into a clickable link?