If you’re attaching your images by inserting them into the markdown like this:

These attachment links don’t work:
<img src="https://stackoverflow.com/questions/41598916/attachment:Screenshot.png" width="500"/>
DO THIS. This does work.
Just add div brackets:
<div>
<img src="https://stackoverflow.com/questions/41598916/attachment:Screenshot.png" width="500"/>
</div>
Hope this helps!
PS I’m using jupyter_core-4.4.0 & jupyter notebook.