I don't know if this is helpful, but when I tried editing [[Allan Shivers]] on en-wiki, which is showing the problem, I noticed that the image appears in "Show Preview", but on saving it goes back to showing a redlink with URL https://en.wikipedia.org/wiki/Special:Upload?wpDestFile=Allan_Shivers_(1956).png

This keeps catching me when I'm editing sections of pages such as [[:en:WP:Help desk]] and [[:en:WP:Teahouse]]. If the section title has no special characters it is fine, and the GET URL generated at the end of the edit has a valid anchor, and returns to the section. But if there are any non-alphanumeric characters in the title, the URL does not match a section anchor, and it doesn't return to the right section.

It's now working for me. As far as I'm concerned, you can close it. (TheDJ raised it on my behalf).

Add myself as a subscriber