Markdown Extra breaks Twig

On a Twig-enabled page I use the following code:

<a href="{{ page.url }}">{{ page.title }}</a>

Which outputs something like

<a href="my-page">My page</a>

Which works fine, until I enable Markdown Extra on my site through the Admin panel.

After that, the output changes to

<a href="%7B%7B%20page.url%20%7D%7D">My page</a>

So {{ page.title }} still works, but {{ page.url }} breaks, I'm guessing because of the quotes. Does anybody know a reason or workaround for this behaviour?

That's pretty strange. Please create an issue here: https://github.com/getgrav/grav/issues