Rich Text Editor styling not transferring to my blog posts

Hi

I am having problems with my RTE. I am using the rich text editor to style my blog, however once I connect it to the post copy, the styling is not appearing on my blog post. Also when I disconnect my content to edit the rich text, it goes completely blank. I have attached a video to show the problem more clearly.

Does anyone know how to resolve this. Thank you.

Hi Alyce, can you share your readonly designer link?