Are you using ACF Pro and have you created templates for your Gutenberg Blocks and called them via: acf_register_block()?
Example:
acf_register_block(array(
'name' => 'accordian',
'title' => __('Accordian'),
'description' => __('A custom accordian block.'),
'render_callback' => 'my_acf_block_render_callback',
'category' => 'formatting',
'icon' => 'no',
'keywords' => array( 'testimonial', 'quote' ),
));