I have tried a number of different ways and am totally stumped. I can render the fields out in the right sidebar and can add more fields etc, but when I try and populate the fields I get a loader in the Gutenberg block and no content.
I have also tried the code from https://support.metabox.io/topic/block-doesnt-render-on-frontend/ . I know that the template file to display the content works in that it outputs the first line -> echo 'test output';, but it throws an error for any data that I enter into the clonable fields saying that the JSON is incorrect.
Sorry for the late reply. But I'd thought I'd respond to keep your forums tidy. I managed to get this working a while ago. Ultimately it is very straightforward and following the help pages and effectively doing this all from scratch gave me a better understanding of how to use the plugin properly.
I think the plugin the awesome and thanks. Keep up the good work.