I incorrectly wrote “attach” instead of “assign”. I know how to use the plugin as I’ve been using it for quite some time on multiple websites.
The problem is that when I add a new slide to one gallery, it adds them to the existing gallery that I have not assigned the slide to. The only way to remove the slide from the gallery I don’t want it in is to delete it, which then deletes the slide from the gallery I want it in as well because it is obviously deleting the slide altogether.
This is not user error and I have not modified the plugin. I repeated the steps on a different website with no other plugins activated and the problem is still there.
Also, any image I upload, under “order” it says 1 for every one of them, and it is adding the photos to the other gallery (not selected) in the #1 position.