Reproduction of the split multi rests issue:
-> Using Windows 10 1909, Cubase 10.5.0
-> Start new project from template “Blues rock” (for instance)
-> Add empty organ (midi) part of 44 bars.
-> Add marker track add a few markers, i’ve placed marker 1:Intro at bar 1, marker 2:A at bar 17 and 3:B at bar 33
-> now you should have something like
-> Select the part open the score editor (page mode) , in score settings set multi-rest to 2
-> also set the marker names to show (menu score -> advanced layout -> show markers)
-> Now we want to split the 43 bar rest at marker A. (so at bar 16 to 17)
-> By double clicking
on the multi rest bar the “split multi rests” dialog shows up, enter 16 as bars split number
-> press OK and examine the result. Overhere the split is always made at the first bar, no matter what number is filled out in the dialog. This is different from the behavior in previous versions of Cubase, not very user friendly, adds a lot of work splitting 16 times and then deleting the first 15 splits again.