Slide Masters

It would be easier to know how to help if you will attach your .story file here. Nevertheless, I will hazard a couple of my early guesses.

1. When you import, the slides bring their own Master layout. If you haven't changed that to your master, right click on the slide and choose Apply Layout.

2. If the circles are shapes on the master, they will be behind any shape or picture on the slide.

Without seeing the file, I would guess that you need to put the circles on each individual slide, or put the picture on the master slide and change to a different layout when you need a different picture. Here's a sample of how I got it to work.