I surely believe that there is a problem with your image you want to upload, because of iOS file handling quirk.

You say "according to iOS Photos App" - are they really jpg files? As far as I know - default is HEIC/HEIF for photos, which will not be recognized by your server. This can cause the error that in your dump you see no values for the "type" key of ["image_file"] array.

On your iPhone device under "Settings" you should check the "Camera" menu and inside the "Formats" submenu. If the "Most Compatible" is ticked, then you save JPEG-s. If "High Efficiency", then it is HEIC/HEIF format. You should try saving a real jpeg file to your photos app, then try to upload that.

Can you check if this solved your problem? If this is not the issue, we can go on further to solve your problem.