I have been experiencing similar symptoms, however the removal of captions doesn’t do the trick. If I publish content immediately (before any auto-saves happen) I can consistently post new articles regardless of captions or number of images. It is not until “updating” the article that the post content starts to disappear regardless of the article being a draft or posted or if the update is done via the auto-save feature.
Number of images (coupled with size of images) may be a contributor to this problem as one of my authors noted being able to update if there were only 5 images on his latest post, but not the sixth. We use fairly high-res images which would explain the discrepancy between the number of images we use compared to others that have posted here.
That leads me to believe there’s a memory limit somewhere along the “updating” path of execution that does not exist down the “publishing” path of execution.
