How do I reorder pictures in a gallery.

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Hey Guys, I am having a problem reordering pictures once I upload them to a gallery.  I can drag and drop them in the correct order, but it always reverts back to the way they were uploaded on the page.  I typically upload on my phone and try to change the order on the phone and that usually doesn't work and then I try again on the computer and it allows me to drag and drop in the correct order but then when i save it it reverts back to the original order.  The only thing that has worked is reuploading the picture I want to display first, which is an annoying process and I don't want to have to individually upload pictures each time.  Please help!