I am surprised it works on your end. In my case, I changed the settings to enable use of wordpress library and still the image was lost when I edited the page.
Here is the link: hidden link
Seems like the form does not keep the image when we edit the page. I have to reupload the image to make it work.
I thought Jetpack site acceleration makes the image load fast so I would be good to have it. Is there a timeline to resolve this issue without making a site slower?