If an Embed is on the topmost position, you can't add a line above it

If you paste a YouTube URL as an Embed at the topmost position of a Page, it isn't possible to direct insert a new block above it.

As a workaround, the user needs to move a Block from below the Embed up to the topmost position. This acts moves the embed a step down to the second position. Now you're free.

-- It should be possible to add a new line (aka Block) above the Embed, without having such trouble.