this has been bugging me for a few weeks, but I always forgot to file a bug report.
To reproduce simply add a passage and click 'save and add another'. At some point every subsequent passage created won't be added. If you cant reproduce, refresh and then try adding multiple passages again. Only 'save and open' consistenly creates passages.
A quick way to check if the last passage was actually saved or not, you can type the last passage's title in the title field to check if it is in the database. If it is, it should be auto completed.
This may be hard to reproduce, but I don't think that I am going crazy. Probably worth looking into