For some reason all div. strings condense neatly, except the celli. I tried copying one part to the others and then changing the pitch (so that in essence they were all the same).
Also, when I do a condense change, there are no celli visible when trying to manually condense them. I do have a lot extra celli when doing a manual staff visibility (although the div is on the previous page). Me is confused.
I trimmed the project down to the issue. The viola’s do condense, the celli won’t. I think it has something to do with all those extra celli div’s that appeared in the manual staff visibility list (or at least, didn’t go away after a previous div or unis.)
You made a divisi in the celli with only soloists. The violas on the other hand, you split into 4 sections. You can see that by the small icons in your divisi change next to the group names: the soloists only have one human figure, the sections are represented with two human figures. Soloists made from a Divisi won’t condense in Dorico for now.