I know. The trouble is that we also invested a lot of time creating the galleries and we also purchased this plugin.
It was definitely the latest update which created the conflict with the featured images. There was no problem beforehand except the rearranging button bug that occurred a long time ago. (I also never got a reply and a solution for this error as mentioned in my first post.)
since the featured image doesn’t show, visitors need to click twice on the image so that the link opens …who does that? you usually just click once and if nothing happens you think there is nothing going on with this picture. so I am still hoping it gets fixed! @biplob018