After Pre15 automatically added beat markers for a music track, I tried to create a slideshow where the stills are automatically placed at the beat markers. There isn't an option to place stills at Beat Markers, but there is the option to place stills at unnumbered markers. That option was not enabled. Confused, I thought that I would have to place an unnumbered marker at the location of each beat marker to get this to work. I put one unnumbered marker at the beginning of the timeline, got lazy and didn't add any more, then I tried again creating the slideshow. This time the option for "unnumbered markers" was enabled. Seeing that the option was ticked, I clicked the OK button. Surprisingly, the stills were perfectly placed at the Beat Markers.
Is that a commonly known issue?