Custom condensing groups not being respected

I have a score that has 3 trombones. I’d like them all on the same stave. I created a custom condensing group for them but it’s not working as expected. In the first half of the piece, it’s breaking them into two staves (Trombone 1+2, Trombone 3). It isn’t until the second half where it uses a single stave (Trombone 1+2+3) as expected.

Is there something I’m missing about why it’s doing this? Is there any option I need to adjust?


Somewhere in between those two screenshots, there will be something in Trombone 3 which the software has determined does not fit on one stave with Tbn 1+2. Crucially, this bit will be connected to bar 6 by a continuous line of music without rests so Dorico will see it as one phrase with one condensing approach. You can break phrases by entering a Condensing Change, ticking the trombones on the left-hand side of the dialog and leaving all other settings untouched.

Cf: Condensing calculations and considerations

I got this sorted with your help, thank you!