Staff spacing changes when a line break is added

Very new to MuseScore, so please forgive me if this has been discussed elsewhere. In the file below, I extracted this part from a score I wrote, and then started at the beginning of the part, adding line breaks and re-spacing measures as I saw fit, being mindful of my remaining space, wanting to keep the part to two pages. Most of the way through, and everything is satisfactory. Suddenly, I add a line break to measure 117, and it changes the staff spacing of the entire page 2. As you can see, it looks like I have room for about three extra staves before that line break is added. After it's added, all of my extra room is taken up, and I don't have room for any more expansion of my last few staves.

I have played around, and there are many measures in that area where adding a line break causes the spacing change, and some that don't - there doesn't seem to be any rhyme or reason.

Can anyone help me fix this? All I want is for the staff spacing that's already in effect on page 2 not to change when I add a line break.

Thanks!