It seems with this version is impossible to add a score to my SongBook. I tried the two methods that worked in previous versions:
1. Open in Musescore (from Gdrive or any other cloud app).
2. Drag and drop via Airdrop from my Mac to my iPad.
In both cases, nothing happens (well, with Airdrop there is a small flash saying "copying", but nothing is copied).
I reinstalled the app from the Appstore, only to see my previous scores in my SongBook are gone...
Thanks a lot for your work!