Multi-bar rests misbehaving possibly because of Staff Visiblity

I hope I can explain this coherently…
I have a piece from a client I’ve been working on. It has a ‘free’ section in the middle, and the hide and show staff visiblity seemed a good way to show all three players in all the parts just for this quite short section, having assigned all players to every part, and hidden the music for the others, except for this ‘free’ section.
To make sure that this section starts at the beginning of a system, I used system breaks to adjust that, and some previous staves to make for a good layout, plus page turns.
In these sections, where the other two players are hidden, I have found on a few occasions that the multi-bar rests revert to single bar rests, even though they are empty in this particular players part. Worrying to begin with, but I found that I could reinstate the multi-bar rest by making the same music ‘fit on one system’, even though the layout remained the same.

I will add, that the file originated in Sibelius, and was imported as an xml file.

I am able to email the file, but I couldn’t make it publicly available.

By all means send me the file to d dot spreadbury at steinberg dot de with full details of where to see the specific problems, and I’ll be glad to take a look. One thing to be aware of is that you will only be able to see multi-bar rests in your part layout containing three players in passages where all three players have rests; if any of the other players has music, even if their staff is not shown on that system, then the multi-bar rests will not be consolidated for the visible instruments.

I wonder whether a better approach would be to use an ossia staff above and below the main staff to cue in the material from the other two instruments for the free passage, rather than including all three players for the whole of the layout?