Reusable blocks are missing in post content

Hello,

I’ve created a plugin that converts post content to speech. It’s not a surprise that on of the basic requirements for such plugin is reliable retrieving post content. I’m using get_post_field('post_content') and everything seems to work fine except one thing: if there’s Reusable Block within posts content – the function doesn’t return it. It gives me all the content except Reusable Block.

Is there some workaround for this?

Thanks!