When a verse slide has been scaled to fit the slide due to too many words, change how the scaling works. Instead of scaling down all the verse slides, just resize the one with too many words. In other words, no longer resize all slides even if they adhere to the number of words on the page fitting.
If that is not possible, then please surface the same message that is visible in a song slide to notify the reason why the font size on other verse slides is not adhering to the correct font size. here is the message:
With the message surfaced, it is apparent of the reason why the font size on all the slides is not accurate font size until you format the offending slide(s) by breaking onto multiple slide(s).