In the First screenshot you’ll notice I have bar 4 selected. When I press alt-down-arrow to start moving those notes down we get the second screenshot after a couple of moves .
The music frame on page 1 is too full already (see b 17) . With those lowered notes, the dynamics line moves down as well and can’t get past the staff below. Maybe bump some bars to the next page or reduce the rastral size
Dorico’s spacing algorithm tends to go a bit haywire when dealing with overfull pages/systems, so you really should try to get that percentage under 100% for a starting point unless you want to do a lot of manual tweaking. Simply putting a Frame Break on bar 19 will do it …
It will be partly because I’ve imported from Finale.
I’d really like the import to be (optionally) nothing more than "the notes. " I.e. exactly the same way as you can get a hold of complex formatted text and put it through notepad++ in order to “start over.”
In Finale I spent far too long fighting its formatting, especially in terms of getting rid of collisions. Soon i hope ‘fighting the formatting’ will just be a bad dream…
In that case, on the MusicXML Import page of Preferences, turn off as many of the options shown there as you feel you can get away with. That will allow Dorico to treat the music more as if you had input it directly into Dorico yourself.