Ive been having this problem too, on and off, for a while - I appreciate this thread is over a year old. Scans, taken via the camera within Evernote scan well, display in the shelf at the bottom of the capture screen, but disappear upon ‘saving’ to the note. They also transfer to iOS Photos well. No amount of time will rectify the problem. In fact, adding an extra scan to the same note at a later date can delete any original scans. The only solutions I’ve found are to a) start another note, in which case the problem is rarely reproduced; or b) add the scans again, to the same note, but this time as attachments from your Photo Library. The problem is intermittent and seems to be specific to attaching the scans to the note, within a note. I am in an iPhone XR, iOS 12.4.1 and all software is up to date. However, the problem has persisted across previous phones probably as far back as the original post.