Hi Hazmi, sorry for late reply. To reorder the new added images, please just drag them to the position before the existing ones. The plugin already supports that.
Looks like this happens only when you create the field with MB Builder, doesn't it? I can replicate the bug with the builder. With pure code, it works.
Can you please try this code in the docs, just to make sure your users have correct permission to upload images. Replace 'subscriber' in the snippet by your user role.
