Adding galleries to pages

I am using slideshow page types for my portfolio galleries, and in past Wpress versions, I would create a new page, click on upload media, upload the pictures, then, rather than inserting into the page, just save as a ‘gallery’. This allowed the slide-show function in my Graph Paper Press theme to function beautifully when I selected the slideshow ‘type’ for my pages in WP admin. If I needed to delete an image or two, or add more, I could do that without losing the entire gallery. With this current version of Wpress, I upload my files via drag and drop, and then select the ones I want and click on ‘create a gallery’. After that, I get to reorder them, but two things have happened. First, it doesn’t seem to want to take my reordering, and just keeps showing the upload order; and the second issue is that even though I don’t want what was in the original gallery, it seems to keep that in the database or something. After my new 11 images were done, it continued to show the older images. But I hadn’t selected them when creating the gallery, only my new ones! The only way I was able to start fresh with a new gallery on the published page was to delete the other pictures, and the ‘delete permanently’ was the only option. What am I not getting here? Or is there no way to do continual editing of the gallery that you’ve published on that page…

Long story but tried to be as succinct and straightfoward as possible. Hopefully someone out there can help? thanks in adavnce.