What I did:
Returned to my Mac in the morning (after leaving all apps open overnight).
Several notes appeared empty — just empty space, no text.
What I expected:
Text that I had entered from previous sessions appears in the notes.
Things that might be helpful to know (Agenda version, OS and model, etc):
Latest version of Agenda (2.0). macOS Sierra 10.12.6, Retina iMac late 2015
I closed the app, then launched it again. The text in the notes is back.