Why are secondary images on new listings disappearing?

[TGKristin]

Some of our images on several of our new listings are disappearing. We tested different formats, sizes, browsers, devices and the images continue to disappear. We have also tried uploading the images directly to the backend product page, through file upload, and through links created in the content section on the backend. Some images will be there for a day or 2 and then disappear and others have disappeared after a week or so. This is only happening to our secondary images. The main image has no issue. Also, listings that we created months ago are fine. It is just our new listings. I have uploaded the images 5 or more times and I am going crazy!! Does anyone have a solution?