7.1 Code Block has mysterious hyperlink

Have you fixed this yet?

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Also, you can use Image Blocks + some CSS to create hover effect.  If you want this, you can share link to 4 hover images, I can take a look

or better is JavaScript (I did for a client last week. I created a gallery, add image to it, use JavaScript to create hover effect. When your client want to change images/hover images, just change images on gallery)