I've got a client who likes to make long pages with embedded images, but there's a problem with the editor on their site that has been causing them and me months of frustration. They can add one image to the body of their article without a problem, including a caption and an alignment. And if they add a second image it also works fine. Until they try to edit the page.

At that point I can see, in real time, the editor WYSIWYG kind of blinks as it is loading. Their second image is pushed to the bottom of the editor box and everything after where that image was inserted in the article is deleted.

This doesn't throw any Javascript errors or cause any errors to appear in the log. I've tried different text formats, turning off and changing the order of CKEditor text filters, changing the theme, turning off contributed modules like the Linkit module, all to no effect. 

We're running the latest Drupal 8. I do have another site that has that issue, although the client doesn't have the same needs and hasn't complained. The commonality is that they were both built with a Glazed theme using Glazed Builder. But this issue happens when editing in the admin theme, so I'm not sure if there is anything there.

Any help would be appreciated.