Test project:
https://drive.google.com/file/d/1bTS...ew?usp=sharing
- on a grand staff, create some notes in both staves and slur them together
- export xml
BUG - in Dorico, slurs are messed up. Also all staves after this grand staff have all slurs missing.
It is best to use the attached rpp. It's the most minimal example I was able to reduce to from a larger work, it took me some time. The problem is most likely caused by cross-staff slurs.
Probably directly related to this
https://forum.cockos.com/showthread.php?p=2153640 .
Reaper:
Dorico: