2, it's not an easy bug to reproduce, for diagnosis. The only real possible fix is to figure out how and why the ball disappears in the first place, but I doubt they've made any headway on this.
I think that on BK in particular, one of these holes in the table exists right in the ball lock area in the upper playfield.
I wonder if it would help if someone was stream/recording their gameplay when this happens. Recording at 1080p someone at FS can zoom out the area and perhaps get a better idea.