Measures Stretching Out

I am trying to get rid of the excess space in random measures in my score (photo attached). I have set the minimum note distance, minimum lyric distance, and have tried to use the decrease stretch feature on these specific measures, yet for some reason there are 2-3 measures in the piece that stretch across the whole page and I'm not sure why? As you can see from the image, it is not because of minimum distance between notes or lyrics, as measures 14 & 15 have both more notes AND more lyrics than measure 16, but I can't get measure 16 to shrink down. Any advice appreciated.