Browser: Chrome 110
OS: macOS / Windows / Linux / etc.
A fallback of {post_content} causes the dynamic tag to fail and for the fallback post content to be rendered. This happens whether the tag requires the fallback or not, and whether the fallback of {post_content} is rendered with :plain or not. Other tags such as post_title and post_date behave as intended.
This is an example of the output on the front end:
{acf_custom_field @fallback: ‘The is the post content … ‘}
And this is the tag in the editor:
{acf_custom_field @fallback: '{post_title}'}
This setup is required in my case because of a need to set the default query type of a component to ‘Repeater’, but to accommodate a fallback to cases when the component is just looping over a Post Object.