Conquering inserting a jump break

It did not work for me. I am talking frankly about my attempt to use a Blogger jump break on one of my longer posts on a custom domain.

Actually, the jump break was inserted at the point of my blinking cursor, as predicted by the attached instructions.

However, there was no "Read more" link - the post was just simply truncated at the insertion point after publication.

So, how can this filed gadget be improved for those of us who paid and are on a custom domain, apart from providing more specific instructions separately?

By explaining how exactly this works with a custom domain because the link is nowhere to be found after publishing my post recently.

In fact, all the text preceding the insertion point of the jump break became immune to the cursor placement!

that is, during editing to remove the visible line jump break inserted, the part of the post above the jump break - the actual "summary" part - could not be selected with the cursor.

That glitch has to be rectified fast before that tab button becomes just another pretty face unused on the post editor panel.