Staff spacing misbehaviour

When I copy the figure from Bassoon 1 into bass clarinet, Bassoon 1 and 2 get mashed together as per attachment. The same has happened with cello and double bass staves in similar circumstances, to the extent that the staves were on top of each other. There is no reason why this should happen — there is plenty of vertical space on the page.
In the cello/DB case the spacing was normalised when I entered some notes in DB. Is there any other fix? (Bassoon 2 has no notes to play on this page.)

I wonder if this is to do with the fact that bar rests are not shown in empty bars? I’m working on a project with similarly invisible bar rests, and empty staves collide in several places with staves above them which contain music.

(Of course, you can use staff spacing in Engrave mode to fix the problem manually, but you already know that.)

It seems that displaying anything at all in the misplaced staves fixes the problem — I had three instances on one page just now, but adding a new time signature on the same page restored normal spacing. But if I deleted the time signature the problem returned.
I’ve got a lot of staves, 30 so far, and I wondered if that might be a contributing factor. Thanks for the suggestion about invisible bar rests — I’ll try displaying them again and see if it helps.

[Edit:] I can confirm that displaying bar rests stops this abnormal staff spacing behaviour.

By way of explanation, Dorico in general doesn’t do collision avoidance for the outermost lines of the staff, so if you end up with a completely empty staff without any notes or bar rests in it, then it can end up being treated as if only the middle line of the staff exists. It’s entirely possible that this will change in the future, but the only case in which it really presents a problem is this one, where you have completely empty staves with no material of any kind in them.

Thanks Daniel. One would think that staves actually overlapping would qualify as a bug. In fact, not even the middle line of the staff is respected: in one case I found the cello staff slightly lower on the page than the double bass staff.
I suppose one could place some invisible item on the affected staff to encourage other staves to respect its space :wink: