Markdown in Custom Blueprint doesn't render

Hi all,

looking for help with a custom page blueprint. I have created a new tab and properties one of which is a markdown editor. The text properties all work as expected, however the markdown editor doesnt seem to work properly. It looks and works fine in the back office, but on-page the markdown syntax just renders as plain text.

I am just using the following in my blueprint yaml
header.releasebio:
type: markdown

and then referencing on twig with {{page.header.releasebio}}

--- twig
{{ page.header.releasebio|markdown }}

[Learn doc](https://learn.getgrav.org/themes/twig-filters-functions#markdown)