Manual condensing not working

In an orchestra score, I want to condense the horns, so that player 1 appears on its own staff; players 3 and 4 appear on a second staff; and players 6, 7, and 8 appear on a third staff; and players 2 and 5 are hidden. See the example below:

Dorico automatically condenses players 1, 3, and 4 on one staff and players 6, 7, and 8 on another, as follows:

So I inserted a manual condensing change at the start of this system to get player 1 on its own staff. See below:

However, Dorico responded by undoing all the condensing:

I’ve tried so many things to correct this, but I don’t know what I’m doing wrong. Thanks for your help!

Le sacre du printemps.dorico (1.3 MB)

I’ve taken a look at this myself and need to call upon the greater expertise of my colleagues in the engineering team. Please be patient: I’ll come back to you when I can.