On my mobile now, which is what I nearly always use for uploading to SAC. This morning, I was adding this new artwork. As one of the artworks was only available during opening hours, I went to Advanced details, to add the appropriate marker.
So, when you select any of the tags, the circle fills for a fraction of a second, then goes blank; Add A Tag gets the filled circle immediately afterwards. Because the drop down box fills the entire screen, you can’t see that the selection was made. It’s only after clicking “Done” that you can see that it has been added.