Hi. I am having problems with ligatures that go across systems. The ligature starts and then continues off the page but the end point is there on the next system.
Also is it possible for a page to look correct in Engrave mode but then when it comes to print, the systems on the first page are too close together.
Best wishes
Peter
Can you show a screenshot of the problem, and/or what you’re trying to achieve?
Do you mean “early music ligatures”, do you mean something like this?
Or do you mean ties…?
I am editing a Mass by Varotto and considerable use is made of ligatures exactly as you have shown in your picture (I definitely do not mean ties). The problem arises when the ligature across two notes spans a system ie last note of first system and first note of next system. I am using the shapes provided in Dorico and I suspect that is the issue ie it doesn’t know that it has to connect between the systems.
Dorico doesn’t actually support ligatures of this kind, so I’m not quite sure what you mean, unless you’re just putting separate notes close together manually.
Ultimately, if the system break is on a beat that is in the middle of a ligature, then there’s not much you can do, except find a different place for the break.
The usual method for critical editions is just to draw a bracket over notes that are ligated in the source. The number of singers that can sight-read ligatures is small! 
Would you really expect a ligature to be able to split between systems, at least in an engraving program? Perhaps one dedicated to early music, but apart from Lilypond there is no other. Personally I would regard a ligature as an indivisible, non-breakable combination. I don’t know what the medieval scribes did. Splitting it would certainly make it hard to read.
