Cross-domain canonical links not generating as expected

Hi. I am finding that when I put external canonical URLs into my blog posts, they are being appended to my site domain. This isn't what I was expecting.

Are cross-domain canonical tags supported? Am I missing something?

I'm quite new to Grav. Thanks

Example.

The frontmatter includes this

routes:
    canonical: 'https://example.com/canonical/url'

The generated tag in the \<head> looks like this

<link rel="canonical" href="https://mydomain.com/https://example.com/canonical/url" />

What template/theme structure are you using?

This is handy for us to understand the context where in this happens :)

Thanks. I am using Quark v2.0.2. I haven’t edited it in any way.