Context : OJS 3.1.2-4
We noticed that the components mark as dependent files (e.g. images) never show up in the drop-down list during the submission process, even after the main submission file has been uploaded.
If I am not wrong, authors used to be able to upload those kind of files. Once the main article was uploaded, a “Dependent Files” section would appear on the second tab (those are screen captures from internal documentation made with 3.1.2-1):
I was able to reproduce the same problem with the OJS demo testdrive 3.x