On a desktop, I can't rearrange photos on new or old listings to put them in the order I would like them to appear. I switched to the old version and it is working.
I've been able to rearrange photos in the new listing template. I use that over the old. Once I have uploaded the photos I can easily switch them around.
Are you creating a brand new listing or using the copy feature. If using new, you need to enter one photo first. click on accept and then where the other photos are placed upload the photos. That is how I do it including the video.