As you can see, it seems like by default Dorico does not accommodate for the text for the spacings of the staff (though it does accommodate for lyrics, of course)
I tried to manually change the staff spacing for this, but unfortunately it doesn’t automatically push the systems after it:
It looks like you have forced too many systems into the one frame - the red box at the bottom-left of your pages that are 100+% are telling me this. Or, Collision Avoidance is turned off (and Dorico is ignoring collisions).
Generally, there should be no need to make manual staff spacing adjustments for this type of thing.
Please upload your project and we can easily check.
I can see why it is confusing: there’s no type of collision changes, casting off isn’t being used and there are no manual frame/system breaks.
This could be the issue:
It’s probably something to do with the additional staff at the bottom of the page. All you really need to do is put a Frame Break at the end of the second last system and things should work out better for you.
Oddly enough, page one in your original screenshot shows the frame fullness at 101.6% and red (overfull). However, when I opened your file, it was green and 100%…