We recently upgraded to 6.2 to 6.4. Whenever I tried to edit the page images are disappearing on the page if I select option like view as published then images are looking fine.
Do you have any customization in dam asset workflow ?
What do you see in the logs ?
Can you see relevant image renditions in crx/de?
can you check the browser console? are you getting 404 error for images or images that are just hidden due to UI code?
could you please share more details?