Hi Richard, Happy Christmas. Whole Measure repeat seems to take over somewhat. In these staves the first is 1 music then 7 rests The second 1 music, whole measure repeat, then restsThe third has 2 Whole measure repeats two rests then 1 music and finally 2 rests.
The Typeset is below and, apart from staff 1 all rests are Typeset as Whole measure repeats.
Even the introduction of some notes in Staff 3 does not change things Looks like a bug. Joe