Hi @Michele2370
My Support case that includes this issue, is still open. I sent videos of the issues today, one was specifically about the missing Calendar Notes function.
Presently you can make a note directly on a reservation, but this doesn't help you for unbooked or blocked nights.
Alternatively, you can make notes on the multi-calendar, but this doesn't help you if you don't have professional tools turned on, or if you have it turned on but you're not at your desktop (professional tools aren't on the mobile app).