This has been the case for some time now, at least back to V.3
Breath marks don’t go where you put them, you can reposition in Engrave mode but the marks don’t display in the correct place, and only on the first part.
1st. pic is where Dorico puts it by default.
2nd. pic is the adjustment in Engrave mode.
3rd. pic shows the wrong position in the parts.
4th. pic shows that it doesn’t display at all in any of the other parts.
That’s by design. Dorico puts a breath mark after the selected note. There are setting in Engraving Options for how far of an offset from that endpoint you want it to be.
When you move a breath mark graphically (or anything else for that matter), and your properties are set to local, it will move it for that layout only. You need to propagate properties, or set properties to global, then move it.
Breath marks are staff items, not system items. So they will appear only on the staff you put them.
Thanks.
I assumed they’d be system items as it’s unlikely that you’d have a breath mark that only applied to some staffs and not others. Anyway, problem solved.
Not at all! Very common for singers to breathe in different places.
Pro tip: assign a key command to Duplicate to Staff Below. It’s life-changing. 
