I’ve been trying out ‘post excerpts’ (using this guide), and have managed to make them work using the shortcode, but this dispays an unwanted "-mark in the full post.
Is there any way of removing this, so that the ‘read more’ button still works, but the full post doesn’t contain this unwanted speech-mark?
Can you share the raw Markdown you’re using to create the excerpt? If there’s an extra mark like that, it’s probably just something you can delete – it’s not needed to create the excerpt.
Also, in case you’re using the Rich Text editor (and not the Plain Text editor), note that you can just click the “Read more” button to insert the split point / create the excerpt.