Well - I need to check with my test install by installing elementor and I'll try to reproduce this issue.
But before I go for that, can you please share the link which elementor template you designed to display single member or supplier post? Can you please share link of that Elementor template?
Well - the thing is that:
The edit form will only replace the post_body (content) part of the post. Anything else in the Elementor template for single posts will still be shown, and the Toolset edit form only replaces the post content part.
So, I've a better workaround for you. I've created a page where I've added the post edit form:
=> hidden link